Should I go to the hospital?

I would wait to hear from your doctor. My doctor told me that as long as you feel 10 kicks every 6 hours, the baby is probably fine. But since you were averaging 4 kicks an hour before, a change may indicate something, or it could just be the baby sleeping, as they do that more at this stage. If you feel less than 10 kicks in a day, go to the ER.