How To Test For Paternity Of A Child During Pregnancy?

I m 23 weeks pregnant and the father of my unborn is saying he wants partenity test that makes me doubt if he is really the father...my first day of my last period was on 28 August 2014 if I m not mistaken and my last day was on 1 or 2 of September 2014 I slept with my ex boy friend on the 12 of September 2014 it was Friday then on 16 september 2014 slept with my boyfriend I m we didn t use protection I took digital pregnancy test on 1 October 2014 it came out as 2-3 weeks pregnant so confused cos I remember sleeping with my ex boyfriend with a condom but I was tipsy I cant remember clearly help me out Doc I m due on 4 June 2015 I was 100% sure my boyfriend is the father but due to what he keeps on saying I m not sure anymore