Cramping and back pain

I had an appointment at the dr yesterday and needed an exam because I have a bacterial infection (although no symptoms of one). She told me the only thing I should be concerned about at this point is red period like bleeding. About an hour ago I am having severe cramping and back pain like I'm being stabbed in the lower back with a knife. No bleeding, normal discharge but this is so painful I can't breathe. I'm 22 weeks. Is this something I need to bother my dr office with or just wait for it to pass considering there's no bleeding?