When did preeclampsia develop for you?

My BP has been pretty low for me throughout my pregnancy so far but today the top number was about 10 points higher than normal. I'm 32 weeks. Doc says it's a little higher than normal for me but still considered in a normal range. I know preeclampsia has other symptoms too, just wondering what other ladies' experiences were. If you developed preeclampsia, how quickly did it progress?