It's been about a week since my boyfriend has ejaculated inside of me. I'm on birth control. I've been having some cramping, muscle pains everywhere and constipation. Sunday the 12th was when I was supposed to start my period and I still haven't received it.
In the past couple of moths I've been losing weight.
I am wondering if my period is delayed by my weight loss and I'm still getting my period symptoms?
I have taken a pregnancy test and it came up negative.
What is going on?

1. It will be too early to test for pregnnacy.
2. 3 days is not really late.
3. it can be from stress, from weight loss

Wait about two week, and if no period, test again, but always use first urine, of the day, as soon as you wake up