If I had unprotected sex, & three days later, I took the morning after pill, & I was on my period & then, the next week I ha my period. Could I be pregnant or not?

It's possible, but not likely. You pushed the limit on taking the morning after pill as they are more effective the sooner you take them. They can cause some irregular bleeding and an off cycle, so that is likely why you have had "periods" so close together.

You'll need to wait 2-3 weeks and try a pregnancy test to be sure.