Blood testing..

I am 4 weeks and 3 days today and I went last week to get my blood drawn on Monday, they called me back Tuesday saying my counts were at like 157 or something around that and said that’s good, that’s a solid positive, but then they asked me to go back the next day to get my blood drawn again to see if my numbers double within 24hrs as they should, so I do and they call me back saying my count was now 384 or so, and said “ oh that looks great!” But THEN they tell me to come back next week (this Wednesday) so they can take more blood and see what my numbers are then!! They won’t schedule a 6week ultrasound for me even tho after each time I get blood drawn they say okay we will call you back with results and schedule a 6 week ultrasound for you.

This is my 3rd pregnancy but my first time with this hospital/midwife. I’m not sure if this is just something they do to make sure everything is still going good or what.. but I guess I’m just curious if anyone else has had to give blood so often? It makes me feel like I should almost be worried about something? Are my numbers not high enough?