My periods will sometimes be on time and then be irregular for months. This last time it came on time august & September & then gone oct-dec14. Now I’m 18 days late and did have unprotected sex. It would have been precum, question is I’m going to see an endocrinologist in a week & half. Can she prescribe birth control as well as check to see if I’m pregnant? I’ve taken 2 test (1 a week after sex and then another the week after the first one) and both have been negative. I’m thinking of taking a 3rd next week to check again.