Brown period

The brown could just be old blood coming out before your regular period. BUT just because your partner didn't cum doesn't mean you can't get pregnant. Pre-ejaculatory fluid can contain a few million sperm, compared to the average 100 million in ejaculation, but it's still enough to cause pregnancy. I don't think you'd be showing signs of pregnancy only a day after having sex, but you may be pregnant from earlier sexual activity. Sometimes having sex can cause your flow to start due to contractions from orgasm and it could've just dislodged some old blood that can sometimes be present before a period. My advise would be to observe over the next few days and see if your regular period starts. If not you may want to take a home pregnancy test or see your doctor if you're still concerned.

Thanks so much, its alot more normal now. Before that time I hadnt had sex for over 5 months, so I'm safe. Besides, he was wearing a condom. Interesting how the human body could be so confusing, I'm almost positive it was just a strange period.