That was the same with me. A constant headache and I'm prone to chronic migraines even before pregnancy. Doesn't matter how much tylenol I take it doesn't help so I just stopped taking it why bother when it's useless?
When it gets bad I just do what I normally do when I get a migraine (minus the pain relivers) and just sleep it off. Some times having a little bit of caffeine helps which is what my doctor recommends
Can also try massaging where it originated. For me it starts usually as a tension head ache so a heating pad and massaging my next helps big time. Other times it's my tempals. So rubbing the side of you head next to your eyes
Oh my I hate migraine headaches I've had them since like 1st grade constantly about every three months up until now lucky I'm 5 months preggo and haven't had any I just prayed to the Lord I dont get one during. Any who sorry nope I've never found anything that gets rid of them I usually sleep them off in a dark room no noise for a wk I have to set an alarm clock to get back up cuz once I'm out I'm out, drinking lots of water and literally making myself eat