My girlfriend has been having her period every 2 weeks on this birthcontrol and we had unprotected sex 2 days after her last period but now is 2 days late on her period and has been spotting. i did not ejaculate inside her but she is worried about pre-eja

Breakthrough bleed: It sounds like she is having breakthrough bleeding and not 2 periods per month. She should probably see her gyn for a change in birth control. However, no birth control is 100% effective, so check a pregnancy test in the meantime as the late cycle and spotting couple be pregnancy. And yes a drop of precum has about 20million sperm.

Three issues: Get her on the right birth control pill so she has 1 period monthly. If you're worried about pregnancy, only practice safe sex (with condoms and birth control pills). She's right to worry about pre-ejaculate, becuase that is the most sperm-concentrated semen of all! she needs a pill with more estrogen, you need to put on the glove for love, and she should not get near pre-ejaculate to avoid preggo.