I am 23 and I had my last period on 4th aug and so the next was due on 5th September. Had unprotected sex on 16th aug n withdrawal method was used. I got it late by 4 days on 9th sep night. The 4 days of delay I had strong nausea n vomiting. I did UPT on 8th morning n it was negative n had beta HCG blood test on 9th morning with a reading of 1.6. Now when the periods have finally come they are very light than usual (as there was no or very less blood on napkins and only when I went to pee there was some of it) and more of watery blood and very less clots and lasted fr just 2 days. It's Dark red and red in colour. I feel weak and have still got nausea but little lesser than before. Also my hands and feet got warm but no fever. Till last month I had normal cycle of 5 days and normal flow. What can this be? Can this be due to iron deficiency or any other reason?