I burped feel like some acid reflux went into my nose now it in my sinuses ..can this happen? and is it dangerous should i go to er?

Not dangerous: See your doctor during a routine visit and discuss your reflux and see if you need a daily medication. In the meantime, lavage the nose (while in the shower let water go in one nostril and come out the other.) Do it for both sides. Consider getting a netti pot or the squeeze bottle to clean out your sinuses. If you have a lot of reflux consider taking an over the counter Prilosec or Tums (calcium carbonate).

Gerd: It's possible for acidic material from the stomach to reflux into the back of the throat and it's possible for the material to enter the back of the nasal passages but it shouldn't enter the paranasal sinuses. If you are experiencing frequent GERD get treated to avoid damage to your esophagus and vocal cords. A gastroenterologist is best qualified to evaluate and treat you.