4 month old has fever of 101.4. acting normal but maybe a bit more sleepy. eating well. will see dr tomorrow am. is this okay?

Yes: Most of the time, a fever with no other symptoms is caused by a virus infection, which usually goes away by itself. The baby is fighting back against the infection, and it is a good sign that he/she is still eating well. Keep him/her cool, and you can wait until the morning to see the doctor. It is NOT an emergency

I'm ok with that: if you are ok with that. You are there and you know your baby best. If he or she is feeding well as you said, having normal wet diapers, I think it's ok to wait until morning. But if anything changes, if you are uneasy at all about waiting, then have your baby seen.