I had sex last night with my bf and my percentage was on like 33% on my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> calendar. But he pulled out with a condom on and I'm on bc but I just looked at my underware and there's like a little bit of brown stuff on my underware. I just noticed it and now I'm paranoid kinda.. even though we have safe sex and everything. . What could the brown stuff be?