Help. Advice please. I will be 15 weeks pregnant this Saturday. I’ve had a nonstop headache since…

Help. Advice please.

I will be 15 weeks pregnant this Saturday. I’ve had a nonstop headache since this past Saturday night. It will ease up and then come back with Tylenol, except for today. It is pounding and throbbing causing me to be extremely tired. I blacked out sitting on the toilet and almost fainted. I was also up all night Sunday with the headache and diarrhea that lasted until Monday. I’ve been eating and drinking water and Gatorade. Even had some soda this morning to see if the caffeine would help but it didn’t. What should I do? It’s getting unbearable.