I'm 22 weeks pregnant and have been experiencing an increase of headaches, is that normal?

Common occurance. Headaches in pregnancy are a common occurrence and are likely related to hormonal fluctuations .Your increased blood volume and circulation may also play a part, or it may be high blood pressure. Stopping caffeine can also cause withdrawal headaches. Other potential headache causes include lack of sleep, sinus congestion, allergies, eyestrain, stress, depression, hunger, and dehydration..