Hi, I am new here also. I didn't really have the same problems you are having with my pregnancy my husband was very supportive, however he did and still does need incentive to help around the house. He will do things when I ask him (sometimes with a little whining though) but he is not good at just jumping in when he sees something that needs done. I had hyperemesis (severe morning sickness) early in my pregnancy from week 6 to about 5 months. I was even put in the hospital twice for being dehydrated and I was trying to finish my student teaching and last semester of college at the same time. Needless to say it was a strain because I was exhausted and horribly sick all of the time, so my husband was kind of thrown into the helping out thing by necessity.
What exactly are you and your SO arguing about? If it is because you are tired or sick just try explaining to him that this normally only lasts a few weeks and then you begin to get back more energy. Maybe you could get him to agree to help out just a couple of days a week, or even just a couple of jobs around the house.
If it is the emotional stuff that is a problem maybe you could try doing something baby related together to get him more involved? Sometimes it takes awhile for men to feel that emotional connection with their baby especially in the early pregnancy because they can't really see, feel, hear, etc. anything with the baby yet where as you are carrying the baby and your body is changing. Maybe you could take some time to pick out baby stuff together, start working on getting baby's room ready, or just start discussing names? It might help him feel more connected with baby and you. Sorry so long