Advice please?

Hi ladies, I’m after abit of advice.. I’m 26+5 with my first and yesterday I had a bad headache which has returned today quite mildly.. I’m a little worried that it’s preeclampsia but I have no other symptoms apart from feeling dizzy every now and then (mainly when I’m hungry). I’m not entirely sure whether to ring my midwives or not because 1. I can’t get there until Tuesday! And 2. It’s mainly behind my eyes so I’m not sure whether it’s my eyesight. I’ve booked myself an appointment with the opticians for next week... do I ring my midwife or will I be wasting her time? I also have my next check up at 28 weeks so do I just hang on or not?