Hi ladies I need help

I was 7 months pregnant when I started having this heart symptom, I started having palpitations and ended when o gave birth but I’m still concerned because my heart looks like is racing through my left breast I’ve been to cardiologist and EKG came back normal and Apple Watch shows 70-80bpm while sitting down but when. Walking it goes up to 122bpm is this normal ? Did this happened to anybody here? Will it go away ? Doctors don’t have an answer for me is an agony to live like this I get shortness of breath when waking I had gotten many blood work to check on everything and everything is fine had gotten Chest x days to check on lungs and everything is fine Ct scans is fine aswell.

I don’t have any anxiety disorder so it’s not anxiety at all

Please tell me I will be fine

I’m 10 weeks Pospartum