Is blood work necessary early on?

Rachael • 30 y/o mama to Ryker and Zayden.

I’m 4 weeks... set up my ultrasound and check up for 8 weeks. Do I need to go in now for blood work or is waiting for my 8 week appointment ok? They didn’t offer it to me and now I see that some people are getting blood work this far along. I’m a first time mom 😬