Exactly as lazy gun has described.
i have years of experience working on maternity along with 6 months on gynae, not as a midwife but hca.
pregnant twice too.
Ur heart has to work much harder to compensate for the extra blood and oxygen it must pump through your body, in un pregnant women these changes in ur cardiovascular system would cause concern to docs , but is totally normal in pregnancy!
as pregnancy progresses ur heart is in fact pushed up and tilted so u will feel palpatations due to this, which again is normal!
Lots of new things are happening to your body, and increased heart rate is one thing that ur not used to, but i can tell u that it is normal.. but do speak to your midwife or gp next time ur there or before if you need to speak to them about this and they will check u over and set ur mind at ease xx enjoy ur pregnancy, u will miss ur bump once the baby comes lol xx