firstly, you are expecting and due to hormonal changes, your moods and fears may be somehow or another amplified. You might have typed in the above 'evidence' based on watever coincidences episodes that may happen to have let you seen it.
Next, this is made worse by hubby needing to be out of town regularly for work and due to the feeling of emptiness, inner fears, jealousy, are brought out to counter this emptiness.
To cope with overwhelming mixed feelings, mind started to search for a resolution and think of the worst case scenarios to prepare itself from receiving any unwanted bad news.
So, what you should do now is to relax. think of the good things that has happened to you and this will greatly benefit the child inside you.
As for your hubby, do not confront him directly.
If it is just a misunderstanding, he will blame you and this is a lose - lose situation. ( worry for nothing and kenna blame for it)
If he admits to something, you are also in a lose - lose situation. ( worry turned to fears confirmed plus watever unbalanced hormones in you currently will affect your unborn child as well as yourself. if you are affected, who will look after your boy?)
Best way is to relax, do some shopping, go out with friends and wait for him to return. once he returns, talk to him about your worries and emptiness. ask him to stay home more often to company you as this is a kind of support you need before the child is born.
even the most hardned affairs prone men will think twice or thrice if the reason you give for him to stay around you is for the sake of the unborn child.
(he stays, you win, means he dun have anything to hide and he loves you. he stays, you win, if he really have affairs, the longer he stays with you, the thinner the affair will gets.)
(he leaves, dun worry, he really have his job to do and in this bad economic times, watever job one has is a way to feed the family so, let him go. he leaves, he may have the affair under wraps and dun wish to let you know in fear that you will be hurt. shows that he still have a bit morals and dun worry, relax and deal with him later when your child is born)
Objective for you in this case is to bear a healthy child first. everything else can wait. also your 2 year old boy will now be starting to understand things and any feelings of unhappiness in the family will affect his childhood as well as his psychological growth into teenage years.
I'm sure you know wats the best for yourself now.