Fhr was 88 before 6 weeks.

Hello everyone! This is my first pregnancy and I am 6 weeks today!! I went to the dr on tuesday I was (5 weeks 6 days) surprisingly I seen and heard the heartbeat! The dr said that I was lucky to see it as it had probably just started beating that day or the day before..my worry is that the heartrate was only 88bpm..is this normal since the heart just started beating? Ive been really worried but the doc. Diddnt say anything about miscarriage or that there was anything to worry about..im hoping it was low due to the fact that it just started beating but I have seen alot of post at 6 weeks that the heart rate was much faster..if u have experienced this or have any insight please let me know!! Thanks!!