Ive had that happen before. With my first two pregnancies I had periods. They weren't normal like a period, in that there were no "clots" in them. The first pregnancy I had three periods, and like I said they were light. The second one, only two. I had a history of very irregular periods anyway so a pregnancy test was the only sure way to find out for me. I sometimes would have two periods within two weeks and sometimes miss one altogether and not be pregnant. I found out later that's an indication of not enough progesterone...You might consider having yours checked. Be sure to use a method that uses saliva since hormones are protein bound. And not to worry, I have four beautiful children.