Sex Problem.. Uncomfortable

So its been about 5 1/2 months since I had our baby, the first few times we had sex a little after my 6 week checkup were wonderful but the past couple times, one of them being last night have just been really weird for me. The second my clothes start to come off I just start to feel super uncomfortable and I have no clue why I don't really have problems with the way my body looks from having a baby. The only way I can explain how I feel is like I'm about to do it with a complete stranger (for me that would be a really uncomfortable situation). I never feel uncomfortable with my husband so to feel this way really just confuses me and upsets me.. I feel like I want to have sex with him so I start to get cuddly and kiss him and put our bodies together and stuff but then I just get hit with feeling uncomfortable.. it almost makes me want to cry when I start feeling that way.. Also I just want to make this clear my husband never forces me to keep trying to have sex even if he wants to really bad, when he realizes I'm uncomfortable or upset he will stop or if I say something about it.. has anyone experienced anything like this.. it really upsets me because I want to do it but at the same time I just can't. I feel upset for getting him all in the mood and then I start to feel like that and can't do it.. he always says it's ok and that he's not mad at me or anything but I really hate doing that..