Long question, sorry!

Emily
Okay, here we go. I have a very regular cycle, like, to the minute! Every 28 days and on for 5-7 days and I've had a period now for 14 years. I had sex 4 days before my period and he ejaculated inside of me (I am not on any form of contraception as we want another baby). Now I know you cant get pregnant unless you are ovulating and I get that, but the one thing that's throwing me is that I came on 3 days early and when I came on it just wasn't the same as my other period's eg. Started off very light and brown which never happens. So as my period continued it was very heavy, like unusually heavy and because of this, I just assumed it was an ordinary period. However, it stopped after 3 days! This has never ever happened to me, like I said, it's nearly a week when I finish! So obviously my question is, what are the chances I'm pregnant? It's now been 6 days since we had sex, so am I able to take a pregnancy test now? Hope that was too confusing!! Thanks