I'm at week 7 nd from last 3-4 days i experienced mild headache, is this normal during pregnancy?

Yes: Most likely it is normal. Probably a muscle contraction headache or possibly sinuses. It depends on where your headache is located and if there are any other symptoms. If it persists though, you should have your physician see you. It could be related to blood pressure, blood sugar, anemia, etc all of which can be common during pregnancy.

Maybe normal: Maybe. Were any medical problems identified on your initial prenatal visit? Have you been pregnant before? Did you experience any medical issues during your last pregnancy? I would want to check your blood pressure and encourage adequate hydration. There are a plethora of common reasons why you would get a headache like anyone else but you certainly need to mention this to your physician if he.