Unprotected sex in may, on birth control, had three periods since, all were short but one. can i still be pregnant? hpt neg

Highly Unlikely: The bcp can make the periods shorter and lighter. By this time, even the home pregnancy tests would be positive. Not really a chance you are pregnant. :)

No...: If the last time you had sex was in May (while on birth control) and you have had three periods since then AND a recent negative home pregnancy test then I think you can rest assured that you are not pregnant.