"Pregnancies" joke

The hillbilly woman went to the hospital to have her
first child. A year later she was back for a second
child. The next year, almost like clockwork, she was
back for her third child. The hospital staff
naturally began to expect her, and she was there,
just like clockwork.
In the twelfth year - she didn't show, and the staff
wondered what happened...A couple of years later she
shows up, but she's not pregnant. The hospital staff
wondered what happened- did her husband die, or what?
When asked why she hadn't been there having a baby
the past couple of years, she replied "No, no more.
Found out what was causin' it."