When did I get pregnant?

I am trying to figure out my timeline of when it happened? I ovulated in November 5th confirmed by both positive opk and temp rise. I had a full and kinda heavy period that lasted from 11/20-11/24. I just tested yesterday on 12/4 and I got a pretty strong obvious positive on a test strip and I also took an FRER and it was a strong positive too. I am trying to figure out when I implanted or if it’s even possible that I’m pregnant and why it’s so strong already? I guess I am still in shock that it has happened! Also my Dr started me on Metformin on 11/12 so I don’t know if it forced me to ovulate again later in the month? Help am I having twins and that’s why the lines are so strong? As a side note I am happy just trying to not get my hopes up in case it’s a false positive. I also called my Dr already about a blood test I’m just waiting for her to call me back because I also asked if I should stop my meds.