Suggestions on having a genetic test done on my lil bean?

First time pregnant here! I had my first appointment yesterday afternoon. I had a quick pap smear, which I was totally afraid of! I didn’t want to bleed and think something was wrong with baby. Afterwards, I waited for a sonogram! I was tracking 6w5d (from my last period), and the technician measured me at 6w1d. She said baby was a little small, heartbeat was 107, which apparently is normal for how small baby is. Does this seem accurate/okay? Is there a way I can possibly get baby to get bigger somehow? LOL. Or it’s just to wait for baby to grow on its own? On another note, my doctor will have me back in 4 weeks. He would like to do a genetic test, which also apparently includes finding out the gender? I felt like it was kind of sprung up on me and he was telling me, not asking me if I’d like to have it done. However, talking to my SO and we both think it would be a good idea either way. What’s the process of a genetic test? I’d be approximately 10 weeks at my next appointment. Wondering if they will have to go in transvaginally again or if it’s just a blood test. Thanks!