Heart palpitations

Do i had my second baby on 27 april pregnancy was normal with no complications and i had a vaginal delivery. I was experiencing heart palpitations during pregnancy and i had holter monitor, ekg and echo test and comes out normal and my palpitations was almost gone by the end of pregnancy. After delivery i was experiencing heart pounding two or three times a day. I am also anxious person and i was on anti depressants last year. So is this hormonal, anxiety or what??? Does anyone experience this.