Okay I really need some help here. I had sex the last day of my period(5th day). My cycles are regular,about 27 days unless I'm stressed,then its 21,rare though..
10 days after I had intercourse I noticed brownish blood,very little,lasted about 3 days and stopped all of a sudden.. a day later there was quite a bit of blood,not enough to use a tampon though,just a lot of spotting,and it was very dark brown.. we used protection but there was a minute he inserted it without a condom.. could I be pregnant

Anytime you have sex, pregnancy will be possible, but given what you describe it would be unlikely. You used a condom... most of the time... and it was the last day of your period.

You can either try a pregnancy test now, it should be accurate at this point, or wait and see what happens when you expect your next period.

Avoid future worry, or lessen it anyway, and make sure he does not enter you without a condom, even for a minute, and consider using another form of birth control along with it.