Baby A on my cervix

I've had two ultrasounds in the last week, and at both of them, baby A's head was pressing on my cervix. They had a hard time getting my cervix measurements but we did get them, and it's normal.

I've just been wondering if he stays like this, am I at risk for preterm labor? I'm only 21 weeks.

I've been feeling my belly tighten, mostly at the end of the day. I also have a giant knot in the middle of my back that usually hurts really badly by the evening as well. No lower back pain or other signs of PTL though.

Anyone have experience with this?