Hey I've had the same sort of rib pain for about a month as well, I'm almost 36 weeks now, and the OB had a feel and told me it was the baby's bottom!

It gets worse when I lie down on my right side (left bottom rib, so I'm figuring when I lie on my right the whole baby gets pushed up further into the left side of my ribcage).

Also when I press it with my hand it feels sore and bruised.

Sounds like there are a few of us with bodyparts doing nasty things to our ribs.

x