Prenatals? !

So I take these prenatals every night (best time they say to take them). My son has always measured ahead anywhere from 9 days to 2 wks ahead. Well tonight just glancing it says to take 2 every time, I've only taken 1 cause yes dumb me I obviously didn't read but should I switch to 2 asap. I will be 35 wks Wednesday, little boy is perfectly healthy no issues at all. So what do you think I should do?