Hello everyone just wondering if anyone can help me im 20wks 5 days pregnant, me and my boyfriend of 4 years split for 6 months i had a new partner i last split up with him on 16th july.. my last period was 11th july and it had finished on 15th july i last had sex with previous partner on 16th july i got back with my partner of 4 years on 20th july on the 15th august im pregnant.. i also tested on 29th july test was negative im just a little worried to who the father is my periods are every 28-30 days so very regular if anyone could help would be great on and ultrasound said my conception was likely to be end of july x