I smoke weed regularly , and since the last couple of months i've been getting a kind of headache in the middle part of the head , is this bad?

Well, it's not good!: Are you asking if smoking is bad or if headache is bad? Can't say that we recommend smoking weed/marijuana/cannabis especially since there's no 3rd party oversight to prove safety & lack of contamination (luckily i think the government stopped spraying paraquat a long time ago). Lots of reasons for headaches ranging from sinus congestion to sinus infections to head colds etc. Go see your doc.