Pregnant after tubal?

In October I had a Tubal Ligation & everything seemed to go absolutely perfect. I actually didn't have any pain afterwards and never even had to take the ibuprofen I did have some abdomen swelling but that was it. I did have a period for a while after wards but the doctors said that was normal and then my period regulated and everything has been great. Now it's the end of April and I've missed my period. Has anyone gotten pregnant so soon after a Tubal?