FTM. Pre-Registering, Possibly Moving?

Hi everyone! So my OB told me to pre-register at my hospital between 13 & 17 weeks. However, my fiancé has been in a long interview process for a new job that could be having us move about two hours south of where we live now, which would mean me needing to change OB's & hospitals. Should I go ahead and pre-register for my hospital? Is it a big deal to change OB's mid-pregnancy? My sister told me not to worry too much, that people give birth at unexpected times and places all the time, but just wanted some insight from someone with possibly a similar experience. Id say the chances of him getting the job is in the 85-90% range.