Why is my friend making excuses not to go to the party tonight?

I texted her to see if she wanted to go to the club tonight and she said she would love too but she isn't feeling well. I asked her what's wrong and she said she had bad period cramps. I was like, "Oh ...well period cramps go away so just take some medicine. You can't miss this party." She said she isn't going and not feeling so well. I told her, "Well you shouldn't let period cramps stop you from coming. They go away fast. Just buck up and shake it off. You're coming! End of story. See you tonight at 10pm." She kept telling me she isn't going and I am being ignorant. I didn't respond. I know period cramps suck but just shake it off. I hate when people make excuses! 😎😠😠😎😠