22wks pregnant. Shortening cervix frm 3.1 to 2.6 over past wk. On progesterone+bedrest+weekly length check via US. Do I have a chance at fullterm bub?

Yes. It sounds like you are doing all the right things. I assume you have also been advised not to have sex. There is an increased risk of the baby being born early but that is just increased not by any means certain. I have known patients with the same findings to have to be induced at term. Best wishes to you and the baby. Hope this helps.