Pregnant..by someone else.

I left my husband months ago. I've been seeing someone else, actually an old friend and we slept together...now to my surprise I'm pregnant. I'm about 6 weeks and have mixed feelings. I'm still legally married. The guy is very supportive, but I'm supposed to go back home with my husband to help with bills. My husband is military and I'm on his insurance, I don't know if he could sue me for using it and being pregnant with someone else's child, or what could happen. My life is a mess, but this baby is so important to me.