Normal?

I'm almoust 37 weeks pregnant, I am very anemic and usualy my bp is a bit low (on border 90/60). I had 2 iron transfusions and feeling really well past two weeks, but today I'm feeling really dizzy. It's been 2 weeks since my first transfusion and about 3 days after the second. My mum took my bp and it was 75/51, tried to lay down and drink something sweet, eat something, but still feeling very lightheaded and dizzy. Has anyone experienced low bp at end of pregnancy? Do you think this is a worry?