Could you have a period then find out your pregnant?

So I'm pretty sure I ovulated sometime during March 22nd-27th. My husband and I BD quite a few times during that timeframe as we were on vacation. I then started my period on April 7th. My periods are typically always 5 days long, heavy the first day and then slowly dies down. This time, I was heavy the first day like usual and then the next 2 days I'd say we're much lighter than normal. The last 2 days there was barely anything, very light. But yesterday (what was supposed to be my last period day) was basically just brownish spotting. My periods never go past 5 days and I usually don't ever have spotting. But all today I'm having the same brownish spotting. Is there a possibility this was implantation bleeding and not my period? Or could it have been my period and I still might be pregnant?