My boyfriends ex was due on februry 18th 2013.. she was unsure of he dates at first then said they it wasn't his for a definite.. but I still feel really unsure and paranoid.. so could someone please help work out the dates of when about she got pregnant.. I got with my boyfriend on may 20th 2013 and they didn't sleep together after that date for sure! Please help :(

It could be him... count 9 months back and you come up with May.

DNA testing is the only way to be sure.