Looking for some support/insight!

Went for my first doctor appointment/ultrasound today. Going off of my last period (May 4th) I should be around 6w6d. Baby is only measuring 5w6d on ultrasound with a heartbeat of 98. I track my periods/ovulation and my app says I ovulated on or around the 23rd of may. We had sex the 22nd and 23rd of may. Going off of ovulation I am only 5w6d or right at 6 weeks, which would be on par with my ultrasound. The tech didn’t seem very optimistic and said she wished the heart beat had been over 100 and was still going off of my last period saying I should be right at 7 weeks, not taking the day I ovulated and would have conceived into account.

I gave birth to my twin boys in 2019, and I had two miscarriages in 2020, both of which I heard a heart beat, which was low and babies stopped growing a few days later resulting in D&Cs. (I also had two miscarriages with same results prior to my twins)

I guess I’m just looking for stories from women who went in thinking they were further along than they ended up being, but we’re still able to see baby and heart beat. Also, if you saw baby around 5w6d what was the heartbeat at? She said 98 was too low but to me that seems pretty normal for that gestation? Maybe I am wrong. They told me to be on the look out for miscarriage symptoms over the next two weeks and are bringing me back for another ultrasound July 6th. I am going to a free ultrasound clinic on Thursday (23rd) and I’m praying baby will have grown and heart beat will be stronger.

I left the appointment in tears and feeling like I’m gonna lose my baby. Any insight would be greatly appreciated!