No sex

I believe my husband of 12 yrs is having an affair we 2 boys already my oldest is 10 and my youngest 7 Am pregnant with our 3rd child who is a girl and it's been about 2 months that we sex once every weekend to none and this past couple of days he has been completely and emotionally distant we have no contact whatsoever if I call him at work he sends me directly to voicemail or if I txt him he won't txt back he comes home from work and he doesn't ask me if I'm ok no conversation nothing I told him about my issue of wanting sex I want that connection he did nothing about it am in breaking point that am becoming very emotional anyone going through similar stuff