Spotted immediately after unprotected sex. have had brown spotting for two days. period was supposed to end 2 days ago.taking yaz (drospirenone and ethinyl estradiol) birth control.help?

Breakthrough bleed: Breakthrough bleeding (bleeding at the wrong time) is very common on birth control. It happens in about 1/3 of users. Its no big deal and usually self corrects over time. If you are not satisfied or it continues to happen then consider using a different birth control method. It is a common side effect and does not mean something is wrong or that the pill is not working.

Post coital bleed: If you had some remaining menstrual tissue that hadn't been expelled during your period, sex may cause it to come out. Female orgasm and sex in general causes some uterine cramping (contractions). The other concern would be a cervical infection and bleeding from the penis hitting the cervix with subsequent bleeding.