I would too! Of course I am no MD! BUT why be in all that pain? 8.5 hours. I prefer Excedrin. Nothing else works for me. God knows I have tried many over the counters and I always come back to Excedrin. They even have Excedrin Migraine now.
Yes, you can take it now. I've got a headache today, too....but mine was because I was worried this morning and cried a lot. What I was worried about ended up being okay, but I gave myself a very bad headache.