bump growing slow

I had the same experience with my first child. Nobody believed I was almost at full term they all thought was only 4-5 months pregnant. Pre pregnancy I was very fit , had a strong core and still swam when pregnant . Was grateful as I have no stretch marks and non eventful epidural free delivery of a healthy 6 lb baby . 2nd pregnancy my tummy muscles not as taut and baby bump size was ‘normal’.