Well first off congrats on the shiny new house. 110K is a crazy cheap when compared to some places such as Silicon Valley. Nothing beats the new house experience, unless you are into fixer-uppers.
That said, expect small delays. It may take a little closer to four months unless this builder is just slapping them together with a cookie cutter and he is very efficient.
My current house ended up taking 2 months longer than anticpated to complete, but I'm a happy camper in it.