It is possible to develop preeclampsia in a subsequent pregnancy, even if you didn't have it with your first. What were the results of your 24hour test? They typically diagnose preeclampsia after two BP readings greater than 140/90 and greater than 300 mg proteinuria in your 24 hour urine catch. That said, you can be very sick without meeting either of those criteria (I didn't). Daily monitoring with frequent blood and urine screens should help detect any lurking PE issues, but it is important to pay attention to any other symptoms such as a severe headache, nausea, vomiting, increased facial or hand swelling. What do you want your doctors to do?
PE is a tricky thing. Doctors have to maintain a difficult balance between what is best for the baby and doing the least harm to Mom. You could talk to your doctors about the recent HYPITAT study which recommends delivery at 37 weeks for gestational hypertension or PE. Here is a very recent "ask the experts" reply describing the American College of OB/GYNs position on delivery of patients with PIH or PE at 37 weeks. They now recommend delivery for even mild gestational hypertension.viewtopic.php?f=19&t=44954