Birth control strangeness

I'm going into changing my status to ttc! I was on tri previfem, and stopped my pill before the 2nd week of pills. My husband and I "did the deed" on the following two days. I experienced some spotting on the third day after I stopped, but it was very light and wasn't much of a concern, so we did it again. Then it came back later, and a little stronger, but still lighter than my usual period, it's on its 3rd, while still remaining fairly light. Im also not due for my period for another 8 days. Because ive been on BC for about 2 yrs before stopping, I feel like I'm still not very fertile. But I started wondering if that breakthrough bleeding means that I can't become pregnant.. This feels like a dumb question but...

Does that breakthrough bleeding act the same as a period, in that I won't get pregnant because I had sex while it was happening? Or is pregnancy still a possibility?