I am 4 months pregnant. But I have a doubt regarding my conception date and its making me stressful. My period is regular (30 day cycle). I had my regular period on 22nd jan 2020. I had intercourse on 26th jan and on 29th I took a ecp. I had again intercourse in later period yet I didn't took any ecp. But again I had period on 6th feb. I am saying it period because I was having heavy bleeding for 3 days. I had to use 2-3 pads daily. Now when I missed my period for the month of march I got to know that I am pregnant. I was happy with the news. I have considered 6th feb as my lmp date. But when I did my first ultrasound on 24th april, my baby was shown 4 days older (11wks 5 days) whereas on the date of ultrasound test it should be 11wks 1 day based on lmp. Now I am worried whether I have conceived after having intercourse on 26th? If so is there any chance that ecp did not work. How many days a sperm can survive? If I have conceived earlier then why the bleeding was so heavy? Will it create any problem to my baby?