There's chronic high blood pressure, and then there's high blood pressure that occurs during the pressure. They're two different things. In general, women with chronic high blood pressure (the kind you have before and/or in early pregnancy) have their pregnancies monitored a little more closely.
Here's the March of Dimes link that explains it all:
Of course, if your doctor knows your medical condition and has reason to think your high blood pressure is more than can be managed during a pregnancy, that's another thing. You know, I'm sure, that you should contact your doctor (or at least some doctor) immediately. One issue may be risks of any medication you're taking on a developing embryo/fetus.