I'm 5 weeks pregnant and my vagina is throbing, is this normal?

Vaginal pain. Obviously, there are concerns that the pregnancy is the cause. Depending on the location of the placenta anvenetia, this may cause engorged vessels in the cervix and creating the pulsing sensation. Positional changes may help alleviate this, but in any case this will need to be evaluated and should be reported to your obstetrician.