My concern when it all comes down to it, is how short a time it has been dating him. 6 months is nothing really and then add to that an unplanned baby, - I can't imagine it all ending in a long-lasting, successful relationship. It's very rare. Not saying it can't happen, but it is very rare (imo).
As to what people think: Being human, people WILL talk. It's what they do. There may be the typical office gossip, the typical "shock/horror" of family/friends etc etc. It is what it is and not much anyone can do about it. It happens. Whatever you do now, will be between you and Jerry. The two of you now have a new responsibility to focus on. People talking? Yep. But you can't change that.