So I had my period this month on the 12th and lasted 4 days. I have had unprotected sex once during my period and once after. And since the last time I had sex it hasn't been too many days since then but I have been spotting. It's a light pink/brownish color. And just wondering what the possibilities were, is it possible I might be pregnant, is this implantation bleeding? Is it possible to get pregnant right after my period.

You can get pregnant soon after your period if you happened to ovulate sooner than the norm. The spotting may be from the recent sex and your period having just ended. Implantation usually happens about a week or so after fertilization, so it would be a bit early for implantation spotting, something most women never notice.

Since you had sex, pregnancy will be a possibility. You'll need to wait and see what happens when your next period is due.

Yes to all the above. You're going to need to wait until you've missed your next period in a month.

There is really no safe time for sex that can't cause pregnancy. Is it implantation bleeding? Maybe but probably not. It is a lot rarer than most people would like to believe. It was probably just some mid cycle spotting. It happens.

This is correct, you may be pregnant, ( or it may have just been spotting, which happens somethings)

There is nothing you can do now, but wait. Wait till it is time for the next period and see if you get it or not.