i was on BP meds with my DS from 6w. they had to adjust the dose once or twice but my BP was kept well in check for the PG. my GP said that sometimes BP problems can stem from some sort of kidney problem that isn't diagnosed during childhood so she included a scan of my kidneys on the referral for my 20 week scan (but was all clear). they decided it was just PG-induced. i never got to the pre-eclampsia stage (i think because the meds controlled it so well) but i did have to do a 24 hour urine collection so they could check for protein (it goes along with a blood test from memory) - it's more thorough than a normal pee test they often do at later appts. i also had GD so had some extra monitoring for both BP as well as the things they worry about for GD. and everything was fine i was induced on my due date but that was more to do with the GD & being on insulin.

i think if your BP continues to rise/can't be controlled then they will look at an early arrival but i'm not 100%.

good luck, hope those meds keep everything in check for you