Actually cramping pain that feels like period-pain in the first few weeks of pregnancy is perfectly normal and nothing to worry about.
I had it with both pregnancies - made me convinced I was about to start my period, but of course I didn't.
That doesn't mean you're pregnant though, don't panic. The fact that you say you're only getting it when you bend down doesn't sound like either period pain OR early symptoms of pregnancy. It could be something completely different.
When were/are you due on your period? If you're worried about pregnancy, I would advise you to wait about 2 days until after the date you are due on, and then take a test. (You can take them as early as the day you are due on, but if you want to be really sure if I were you I'd wait until about 2 days later, because it'll be even more accurate then).
If you get a negative test but you are still getting the pains, go and see a GP.