New to BBT

Ladies!! I'm new to taking my bbt and need some quick info and opinion. I started taking my bbt during what I think is my first menstration after birth control was removed(about 28 days ago). I am noticing that my bbt was elevated for the 2 days I had my period and 3 days after my period. I did not take my bbt before my period at all. I am wondering if this is normal or if it could of actually been implantation bleeding and not my period.