Help please

Hi I found out I was pregnant on Sunday my last periods being 27/9/19 but I’m very irregular due to pcos so my cycles are all over the place usually and 35days I had a progesterone blood test on Friday before I knew I was pregnant. I had a scan today and they could not find a gestation sac but said it may be to early my they sent me for another blood test and my progesterone has dropped from 50.4 on Friday to 46.3 today and my hcg is 888 she said she is not to worried about the progesterone at the moment I have to go back on Thursday to see if my hcg has double. I have had a previous ectopic with no symptoms so I am panicking does anyone know of progesterone dropping a little but everything being ok? Please help thank you