I'm 23 years old. 5'7" and was about 126lbs at the start of the year. I decided to start running as part of my New Years Resolution. I'm in no way a "runner" and much more than a mile or so is tough but I have stuck to it. I am now 120lbs and my period is late.
My last period was on Jan. 22nd. My periods are usually 28-31 days apart. I am now on day 34 with no period. I had sex on Jan 26th (still bleeding a little) and again Feb. 23rd.
I took a pregnancy test this morning and it was negative. I did however drink 4 bottles of water in a short period of time prior to the test. (wondering if it was too dilute?)
I'm wondering if in fact I am not pregnant from the sex on Jan 22nd...how do I know when my body will ovulate again? Could I be pregnant from the sex on Feb 23rd and not know yet? How long does it take to ovulate again? (I did gain a couple pounds over the weekend...was at home w Mom's good cooking!)
It sounds more like amenorrhea due to anorexia (insufficient caloric intake). Your BMI is down to 18.8, and you may not have enough body fat to ovulate (your body thinks it's a famine and it's not a good time to get pregnant).
You can check whether you are ovulating with either basal body temperatures or an ovulation predictor kit. Usually, women ovulate about 14 days before they expect their periods, so it is unlikely that you got pregnant from either of the acts of intercourse you mention.
There is a very small possibility that you ovulated very late due to the rapid weight loss, in which case the pregnancy test would be positive about 15 days after the intercourse, and definitely within 30 days. Good luck!
-- Cynthia, CNM. PhD.