Ob-Gyn questions? Ask a gynecologist online.
I'm sorry you feel so poorly. With your history of preeclampsia in the past you do need to stay vigilant. Have you been in to the OB triage unit at the hospital? What meds have you tried? You can try tylenol, increased water consumption, or caffeine at home. If you go into triage, they may be able to give you something else such as IV fluids, reglan (a nausea med that sometimes helps with headaches), or other pain meds.
So, basically, I recommend that you go in for an evaluation. That way, someone can lay eyes on you and see if there's anything they can do to help you.
How are you feeling? Is your headache any better? Have you been able to be evaluated in person?