How long to nap after first shots?

LO normally naps for 1-1.5 hours.  He got his first set of vacc. shots today.  Napped and woke up on his own, took a full feeding and had a bath, but went right back to sleep.  Has been napping for 3.5 hours since.  Should I pump and let him sleep till he wakes on his own or should I wake him to nurse???

TIA