Pregnancy after chemical. Not as far along as I thought?

Abigail • Pregnant after chemical in December/January. So excited 👶💜
So I'm December I got my BFP. Only to start cramping and bleeding on New Years until the fifth at around 4w4d. I am now pregnant again (no period inbetween) and I went to the hospital last night for pain on my right side and they said my HCG levels are at 533.6 and judge of the bleeding I had the 1st-5th I should be around 5 weeks but the 533.6 level isn't good for 5 weeks those levels put me around 3 weeks! I'm so terrified I'm losing another baby. I took a clear blue digit on Monday morning (FMU) and it said Pregnant 1-2, and another again Tuesday night around 10 pm and it said pregnant 2-3. So I'm just scared I'm having another miscarriage. Has this happened to anyone else ?