Thanks everyone for your input - guess I'm feeling a bit put out seeing as DH got to name DS and we agreed if we had a girl that I got to name her (guess he didn't think we'd ever have a girl - neither did I tbh!) and now he seems to have taken over the naming rights.
I guess the reason why I'm so stuck on Jessie, Katherine and Jane are because they are mine, my mum and my MILs middle names and I always wanted to incorporate those names somehow.. DH wants Jessica Susan (Susan is both our mums names) because it would be another 'family' name but we just don't have a Jessica in the family so I don't get how Jessica would be a 'family' name.

Nae - My first suggestion when pregnant with DS was Jessie Jane, but then we found a porn star with the same name

Babyluv - I dunno why, but DH just doesn't like Jessie as the first name and only sees it as a nickname. It's my middle name so I've always loved it, but can't seem to convince DH

Nai - I had Jessie Katherine Jane all set when pregnant with DS, but seem to have gone off a little bit cause DS only having one middle name.

sunny - I guess it's cause I'm not that girly that I'm not a huge fan of Jessica

nickers - I wish I could convince DH, I dunno why he just doesn't like it. Then again, I will probably be the one filling out the birth certificate stuff

Thankyou all again for ideas. I guess I'll just need to sit down with DH and talk through the options. He knows I'm stuck on Jessie, and that I want family names, but I just dunno atm. At least I've still got 17 or so weeks right?!