A 609 FICO generally reflects a credit profile that can be improved. If you are slammed with collections and charge-offs, your FICO will usually be lower. I'd recommend having a good loan officer look at your credit report an make suggestions on how it may be improved. There are lenders that will work with your score, but you're not going to like the rate/fees of the loan. Oftentimes, spending a little time and/or money to get your FICO better will save you a bunch of $$ down the road.
And to answer your last question, your FICO does not automatically jump at any interval, 1-month, 3-months, 1-year, etc. You need to take a hands-on approach to managing your credit and you'll see that the FICO will jump based on the actions you take.