Headaches after Sinus Lift Procedure

[SLP]

I had a sinus lift procedure done about 3 weeks ago. I went through a tough initial phase with a lot of pain since I caught a cold the same day after the procedure. During the first week, I had a lot of sneezing and coughing due to my cold. I had a prominent swelling in the area for about a week and a lot of pain as well. The second week was better and my pain and swelling had been going down. Since the last week or so, I have been experiencing headaches especially during the late night and early morning times. The headache seems to last till mid-day. It is not severe but still strong enough to be bothersome. There is some pain in the area of the procedure along with the headache is in my side of my forehead and also some pain that seems to radiate to the side of my neck.

The headache has become an almost constant feature in the last week or so. I was initially thinking it must be to do with the surgical wound still not fully healing, but now my suspicion is that there is some complication affecting my sinus that is causing this. My cold is almost completely gone now and except for a few occasional nasal blocks, I do not have any cold symptoms or sinus infection symptoms such as secretion from my nose etc. I am able to manage the headache with an Advil, but I am not happy with this temporary fix. I do find a couple of times a day a small bone graft particle in my mouth.

Should I see an ENT specialist about this? My dentist seems to want to wait and see.Should I ask for the bone graft to be removed? Please help.