Faint line then perriod??

I am usually on a very regular 28 day cycle with that being said, I took an at home test 2 days after my missed period and got a faint pink line after months of trying for baby #3. My husband and I were so excited! Then day 3 I started. This has been the heaviest cycle since child birth! Is there any way my hormones before my period could give me a false positive or was there a possibility that I was pregnant?? Thanks for any insight in advance!