When thinking about entering an ultrasound program, you need not be concerned so much about certificate vs. degree. What is important is that you go to an ACCREDITED program, whether it is college or hospital based. An accredited program allows you to take your registry (licensing) exams upon graduation. Once you get licensed, you will never be asked about your schooling again. An employer does not care what route you take to get licensed, they just want you to have that license.
Don't waste your time or money on a NON-accredited program. Upon completion and graduation from a NON-accredited program, you must work in the field of sonography for a full year prior to taking your licensing examinations. But, you will have a hard time finding an employer to hire you, unless you are licensed.
I would suggest you observe an imaging department to get an idea of what ultrasonographers do daily. There is much more to it than scanning pregnant women. Most people have no idea how much is involved in this career!
You can find a list of accredited schools in your area, by searching "diagnostic medical sonography" and your state at the following site. There are links provided for each program, which will give you additional information (including course duration):
There are seven accredited ultrasound programs in CA....
Many people, myself included, go to school to become a radiologic technologist, before continuing to ultrasound school. In fact, it can be difficult to get into u/s school without the RT license. There are many more choices for schools for x-ray in most states. You can find them here, by searching “radiography“ and your state:
The pay for ultrasound technologists will vary, depending on experience and geographical location. The American Society of Radiologic Technologists just did a large salary survey. You can see how much a RT and/or ultrasound technologist averaged, per year, in your state here:
https://www.asrt.org/media/pdf/research ... sation.pdf