Low hcg

Hello, hoping to find success stories in this group. Back story... I did a frozen embryo transfer on May 8. Today 10dp5dt my hcg was only 33. I was shocked as I’ve been getting positive first response test since Tuesday of this week. My nurse called and said my blood test was positive and congratulations and that Monday they want to see it at least double. With my last pregnancy my first beta with my daughter was 623, super high so I wasn’t expecting that but was praying for 150 ish so when she said “33” I started crying. I’m scared it’s a chemical, praying baby implanted late. I started at cramps today but had those with my daughter all through first trimester.

Update:

Second beta went up to 56. Drs think it was a late implanter after fet. Repeat beta in two days to continue to see levels rise. So far cautiously optimistic.

Update #2

Beta #3 came back at 106. Drs happy with the pattern and rise! First ultra sound 6-6-19, I will be 1 day shy of 7 weeks. Praying for a healthy strong heartbeat! God is SO good!