What Causes Weakness,tiredness And Nausea Early In The Morning?

hi, im jwala, i got confirmed while having a loop, my delivery was a normal delivery and i got my family planning done on 27th november 2013,the next day of my delivery.now my baby is 2 months old.now i have nausea early in the morning and i feel very weak and tired.during my second pregnancy i had same kind of symptoms.is there a chance of failure of the operation.my gynaecologist is very well experienced.