Ever since i told my boss that i was pregnant he's treated me differently, down right dispicably to be honest

i've worked for a Head-Hunting firm for the last 4 years, it's a high stress fast pace sales environment only 6 of us but practicaly all girl consultants super skinny is encouranged you know the male chauvanistic c**p...
It started a few days after i told him beginning of Jan when he said that wouldn't be doing my 'one to one' for me this year (plan for the year ahead) as i wouldn't be here in a few months, try 6 months! looking at maternity leave end of June! i was so shocked and taken aback the he's just been ignoring me, written me off almost, making comments about my weight and i've gone from a slim 8 to a 10 i'm not even in maternity clothes yet! Yesterday was the worst we were having a meeting in his office when he said he was going to organise a night out for the office as he wanted to get really drunk then he turned to me and said you obviously won't be coming will you? i said what i'm not invited? and he happily gabbled on about the nights plans. He's assumed that because i'm not drinking i won't be coming, i feel so sad

to be completly side lined especially that i was the first consultant he ever took on 4 years ago and he has know no respect for me. I couldn't sleep last night as i was so upset and called in sick today.
Sorry for the rant girls it's just so sad to be treated like this.