There is a small bump near my hair, on my forehead. it has been there for about 4 months. can a pimple last that long? and it hurts when i press it.

More likely a cyst: A pimple is an active infection of the hair follicle and the overlying skin is mildly red. Some tmes a follicle may become blocked and a sebaceous cyst will form, which feels like a hard nodule in the skin layer, but the overlying skin looks normal. If this has enlarged recently, it should be checked urgently by your doctor, otherwise, have it checked at a routine visit. Other dx are possible

Pimple??: Does it look like a pimple? It would be unusual for a pimple to stay for four months and not change in some way, either by growing, or bursting and draining, or by gaining some more pimples nearby. This should be looked at more formally by a doctor to make sure.