I have slept on my stomach since I can remember. Recently I found out I am 5 weeks pregnant. The other day I slept on my stomach and my husband said I would crush the baby. Is that true??
No. Size of the uterus is the determining factor as to whether it can "smush" up against your vena cava, causing dizziness when you're flat on your back, or whether your baby gets cramped when you sleep on your belly.
You yourself will get uncomfortable enough to change your sleeping position.
Your uterus isn't even big enough to rise out of the pelvis and become an abdominal organ before 12 weeks. There's about as much chance of "crushing" your baby as there is of your husband's penis battering him (or her).
(That ought to quiet your husband's fears.)
For the record, lie on your left side after 12 weeks. The right side is OK too, but the left side is better. Lying on your back later in pregnancy is the worst position.
In early pregnancy, (less than 12 weeks), any position is OK.