Can pressure on belly while pregnant harm the baby? Is it possible to squish the baby? Or break the baby bones? Boyfriend was laying on top of me

Well protected. while later in the pregnancy it would be quite uncomfortable to have much pressure on your belly, your baby is well protected with the amniotic fluid, the thick muscle like layer of uterus, your belly fat and abdominal muscle. We worry more about sudden impact injury like auto accidents or falls directly onto the pregnant belly.