I think if you decide to go ahead with the pregnancy you must be fully at peace and prepared to do so as a single mum. I wouldn't be relying on either of these guys.
I also don't think you should do the paternity test behind guy number one's back. I understand the desire to keep the paternity issue from him if he doesn't need to know, but even if he then commits to you there will always be that hidden secret in the back of your mind. A lie is no foundation on which to build a relationship, let alone a family.
Good luck with it all.