Heavy implantation bleeding?

Cheyenne

I got my first BFP yesterday morning, and I was thinking I was about 5 weeks. But the more I think about it, the more I think I’m closer to 9 weeks 😳 my “period” last month was late and very short and mild but my pregnancy test came back negative so I didn’t think anything of it until my boyfriend and I starting thinking today... My symptoms more align with being 8-9 weeks. Is it possible that my implantation bleeding was just a little heavier than most?