I'm pregnant and my boyfriend doesn't believe me !

So May first me and my boyfriend were in bed together and we fooled around he fingered me and we got very close to having sex but we didn't he had the condom on and everything but I was to scared so we stopped ! I thought I was doing the right thing. My stomach started hurting and I ended up not getting my period after so I decided to go to the doctor mean while my boyfriend dumped me ! It turns out I'm about 3 weeks pregnant and it is exactly three weeks from when we fooled around ! I told my doctor and he said it could be a pre ejaculatory pregnancy but my boyfriend or now my ex thinks I made it up to get him back and thinks its impossible ! I don't know how to explain that this is real and really happening please help !
I'm pregnant and my boyfriend doesn't believe me !
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