Is my girlfriend pregnant?

[dainegleesac]

My girlfriend and I had sex a few weeks back. I did not come, and checked the condom afterwards. She just switched birth control pills a week before, from one brand to another. The new pills were supposed to shorten the cycle to 4 days. After this, for 2 cycles in a row, she had a very light period for only one day during her cycle. Is there any possible way she could be pregnant, or is the oddity in her periods attributed to the switch in pills?
Thanks

 

[snowbee]

If you are having sex there is always a very slight chance of getting pregnant whatever contraception you use, however in your case I would say it is very unlikely and the changes are most likely to be down to the change in pills and her body adjusting to them. If she is taking the pills correctly and you are using condoms you are highly unlikely to get pregnant. Sounds to me like you are both doing the right thing to avoid pregnancy.