Aww your mates are just trying to be good friends...
Im guessing they've seen you hurt over your ex before..
And noone likes to see their mates upset or whatever.
Its up to you weather you want him around now or not.
If you give him a chance and he messes it up, then you dont have to see him during your pregnancy if you dont want to..
Dont just not see him because of what your friends think either though.
Im sure they'll still be there supporting you whatever he does...

xxx