So this pain just started earlier and now my lower stomach is starting to get tight, what does this mean?

We know nothing about you, and would have to, just to even start to guess.
Pretend you are in a doctor's office, and answer every possible question you can think of.
Then, after all that, localize the parts of your torso better.
It still might just be all guesses, because there are so many possible reasons for pain.

It could be anything from a pulled muscle, to gas, to something serious.