Try not to stress about it, Sarah. Remember... your body is designed to birth babies. Bubba's head is also soft to help squeeze through.
Also, OB's tend to see pregnancy and birth as something that "happens" to our bodies... not something that's normal and natural. They focus on the possible "problems" rather than the actual "possibilities" (of course... that's a general statement... I'm sure there's exceptions ).
You can do it!