Periods suddenly irregular

[Alt123+]

I was wondering if you could give any insight about my suddenly irregular periods. I got my period at 11 years old and had regular periods up until 18 when I went on birth control. Growing up I had acne on my face and sometimes my back and did accutane at age 13 and 16 which I really regret bc I can now control it with topical treatments. I also lost a lot of hair on the second round of accutane which never grew back but the shedding stopped after taking it. The months before I went on the pill my skin was clear and my periods were regular as usual. I stopped the pill last May because there was so reason for me to be on it and I wanted to monitor my cycles. My periods were regular 31 days for 3 months and then jumped to 35-39 days when I went on a two month trip to Europe. After my trip they went back to 33,34, and then a 30 day cycle of January 2023. Then I went back to school and reverted to old habits of forgetting to eat/ long walks to class and exercising pretty regularly to manage stress. I ran cross country in highschool and my periods were fine but I ate a lot. I missed my period the month of February and March and finally got it in April. I had an ultrasound in February showing polycystic ovaries. I then asked my doctor for blood work to check for pcos which all came back finally and I had a 17-OH of 410 ng/dL which was out of the range of 290 but my doctor didn’t say anything about it. My estrogen was 197 pg/mL and my testosterone was 43 ng/dL (13-71 ng/dL) and free testosterone 2.8 (0-4.2 pg/mL). My DHEA s was 371 ug/dL with range of 430 ug/dL and my FSH was 3.0. My prolactin was tagged as high at 24 ng/mL with 23 being the range. I think this was right after ovulation or in luteal phase bc I got my period 10 days later for the first time in 2 months in April. I’m 23 and 5’7 and weigh 119 lbs. my period is late again this month at day 40 so something is off. I lost weight in January and have continued to lose pounds after having stopped all exercise and trying to eat more. I’m normally around 127 lbs. I was stressed and forgetting to eat at school this past semester but I bumped up from around 1300 calories a day to 2000 recently. I also had a 1 mile walk to class which I did 4 times a day and remember feeling like I was going to pass out on the way back from class having not eaten for 6 hours. By eating more consistent meals I already feel so much better. I don’t ever feel lightheaded if I eat 3 full meals a day. I also have terrible health anxiety and anxiety in general so I was stressed about school and then not getting my period for the first time made me 100 million times more stressed. I was always on birth control in college so I guess I’m learning how stress and not eating regularly affects me. Running in highschool I had my moms cooking and I ate as much as my dad to maintain weight and I have continued running for fun in college. My TSH also went from 1.4 to 2.98 in the past 6 months so I thought that was weird as well. My doctor said I qualified for pcos based on the missed periods and ultrasound. I told her I lost weight and wasn’t eating a lot of carbs but she said bc I wasn’t anorexic it wasn’t an issue. But I have no hirsutism, weight gain, or painful periods. I have been having trouble eating enough to gain back weight. I did start breaking out 3 months after birth control but my skin has cleared with tretinoin. I have read all of your articles about HA vs pcos which have been so helpful but I’m still not sure exactly where I fit yet. Is it possible to have irregular periods for a few months bc of stress and under eating and get back on track when those things are resolved? I have had cramps for 10 days and swollen breasts and 1-2 breakouts but no period. I am also not sexually active. Thank you.

[Jeslyn]

I don't know enough to make sense of all those blood readings, but everything else you say makes it sound like exercise amenorrhoea. From a biological point of view, our menstrual cycles exist to support reproduction. If your body is getting signals of stress and food scarcity, it makes a "choice" to avoid pregnancy.
It can take a little while to bounce back. You just need to make sure you are eating enough (or even more than enough) calories to account for what you are burning in exercise. You also need to find ways to manage stress. Trust your body though. It knows what it's doing. It's responding to the environment you have put in place for it. If you adjust that it will adjust too.