Before you worry about telling him, have
you told those closest to you?
I am assuming you aren't together anymore
as you said he was your then boyfriend?
Have you told your mom? I guess your
sister knows from your previous post.
When I told my baby daddy, I knew it
wasn't what he wanted, but also I knew him
well enough to plan how to tell him, I
wrote him a letter and forbade him to read
it until he was somewhere safe and
unlikely to be disturbed. I promised in
it that I wouldn't try and ring him or
anything and just waited until he got
home. 7 hours later her turned up. I
cried, we cuddled, ended up in bed

and we're still
together.
I guess if he needs to know you will just
have to tell him outright.
Be prepared for the typical guy re-action
though - that he will deny it being his,
will say you must have slept with another
guy and such like.
But once you have told him, unless he
wants to pursue it further leave it.
Just my personal opinion and some will
disagree I know.
Weigh up the pro's and con's - what can he
offer? Do you want him involved with the
baby (if you are indeed pregnant)?
Is it worth a paternity test to get him to
pay up with child maintenance payments and
so on?