Hello madam,I understand your concern.in my opinion the weakness and dizziness might be due to anaemia caused by low iron.dont worry this is common thing seen in many pregnant women.you just need to increase the intake of iron .check the Hb at required intervals and adjust iron dose according to that.in addition to that you need to have good nutritious diet like egg white daily,milk,fruits and iron rich diet like green veggies,onion stalks,zaggery,figs,dates,beet root and liver.by following all the above you will definitely will be free of anaemia and become healthy before term.all the best...