Daily Palpitations could this mean a pregnancy hormone change??

Hi all, me and my other half have been txt for over 3years now with no success. I have a 12year old from a previous relationship. Anyway, im due my period in 4days time and have my usual sign of cramping and sore boobs but for a week and a half now I've been having terrible daily palpitations which I'm not used to having normally. I've not long since read that sometimes a change in hormones and blood flow due to pregnancy can be a cause of this. Just wondering if any of you ladies have ever experienced this before and actually found you were indeed pregnant?x