My last period was on January 25th 2013, my period ended Thursday January 31st, and on Friday (the first) I had unprotected sex although he didn't finish inside I'm aware of precum, exactly a week after having sex I had a sort of brown discharge when I wiped but it only lasted for about 3 days, then a week later I had a clear white discharge in a big quantity. I had heard that there were very little chances of pregnancy the day after your period, but my period was due today and nothing. Im very very worried, should I be scared? I thought that the brown discharge could be implantation bleeding, but isn't that supposed to happen when your period is due? Wouldn't it have been too soon back then? Im really scared, please help me

Any time you have sex, pregnancy is possible, so yes, you could be pregnant. At a day late it's way too early to test, and really, a day late happens all the time, and is not even considered a concern.

Wait until your period is at least 2 weeks late, then test using first morning urine. If that test is negative, wait for your next period. If you miss it as well, test again or get a blood test done.

Good luck.