Renee-were you free motion quilting when you were having problems? Sometimes I have problems with my machine if I am using a different kind of thread and I am free motion quilting.
I recommend rethreading your machine (and the bobbin) with thread you usually use and try just sewing a normal seam and see how your bobbin acts. If it is still messing up, then you may need to have your baby checked. If you have been doing a lot of sewing, it may need to be serviced more than once a year. If it is sewing just fine, then change just the bobbin and see how it sews, then the top thread, etc-changing (and then sewing) just one thing at a time and see if you can then figure out what it is that is making your machine not work correctly.
I changed my stitch setting to zig-zag once and forgot to change the foot-when I started sewing I "jammed" my needle onto the foot and it threw off the timing in my machine--it messed up my tension and was a costly mistake to repair. The repair man told me I should hang a photo of my credit card over the button to switch to zig-zag so I would remember to change the foot next time!!
Hope you get it figured out and let us know what the problem was--we can all benefit from each others knowledge!!!