I Was Missed My Period So I Was Consult My

i was missed my period so i was consult my doctor last month to check if i am pregnant or not,she do trans vaginal scan and blood test all are negative and then she prescribed sysron n for 5 days after finishing my medicine i got my period but it looks more water with blood,this is the first time i saw my period look like this
what is the reason,and am i pregnant