I just had a baby 12 weeks ago, my husband and I have had sex, my 2nd period isn't normal, could I be pregnant? Or are periods not right after pregnancy?

Well, it is very easy to get pregnant right after having a baby, this is one reason many doctors recommend that you use protection if you are not ready to be pregnant again.

With that said, are you breastfeeding?

Usually periods are not back to normal for several months after delivery of your baby. What do you mean by not normal. I need more info to be able to answer your question better.

I breast fed for the first 6 weeks. New Year's Eve my husband and I had sex with protection.
He did his thing and then put it back in without protection for a minute. I started my first period Jan. 3. it was like a normal period. It is now time for period now, but it's not blood, it's just a little brown every now and then when I go to bathroom.

It would probably be advisable for you to take a pregnancy test. This may or may not be normal for you and only your doctor can safely guide you in the right direction at this point.