How can I join back a group?

K
I was part of February 2016 babies group and I was trying to join the group for March babies (my edd is 02/29) but accidentally left the Feb group. Now I can't find a way to join any of the two as they are not offered in the list of pregnancy groups. Pls help! I only have a few more days to go but I've been really enjoying support of women who are due around same time as me