heart palpitations

i know heart palpitations and a faster heart rate can be normal in pregnancy, but to what extent? i almost constantly feel like my heart is beating out of my chest and maybe twice a day i feel like my heart skips a beat. i see my doctor wednesday and will ask about it then but until then, is there anything i can do? i cut caffeine down but if i don’t drink some caffeine i’m super nauseous. i’m 22 weeks pregnant and been feeling this since about 19 weeks but feel it getting worse.