6 weeks exactly baby's heart rate was 109

Alexis • 18 😊 mommy to be 😍 blessed with a little boy🚼 EDD; July 9, 2016 🙌
I went to the e.r. for really bad cramps, they did an ultrasound and baby's heart beat was only 109 bpm I thought it was supposed to be a lot higher! Am I over thinking or is it normal?? Ftm here, thanks for your opinions in advance.