Fluctuating period

I got my period yesterday, and it was very abnormal.
First of all, I was a week late, and when I got it it was very light the entire day... but when I got home last last night, it was started to pick up in heaviness.
(on the first day, my periods are ALWAYS heavy and very painful. Yesterday I couldn't even tell I had my period.)

So, today, me and my fiance were together... my period was pretty normal, except fluctuating in heaviness. Then we were alone together at my house, and I had no blood flow, so we ended up having unprotected sex.
Immediately afterward I went to the bathroom and noticed that I had some blood flow again, but he had none on him from us having sex.

Could I be pregnant?

Also, I thought I could have been possibly pregnant before-hand, because of my abnormal period; but he never ejaculated inside of me before.

Any comments toward this will be greatly appreciated!
Thank you!