pain in left lower back

I think I hurt it bending down at work but I honestly can't remember, it's just it hurts when I sit or bend but not when I walk, but when I lay down on it; it hurts with pressure as well. it's from my lower back to the front of my left hip, I'm currently 5 weeks pregnant, no bleeding or anything other than the pain, should I be worried? I've been taking Tylenol but hasn't done much, it is a big nusience considering I bend down a lot at work, sometimes there's so much pressure it'll go to the middle of my lower back like pressure on my spine, any ideas?