A little bit of pain

Hello everyone, I’m having this little bit of pain at both ball, it usually happens for 20min-30min and then gone.

I’m currently focus on length, I follow the wiki and do manual stretching. I did see some progress. But usually I encounter this little bit of pain.

Is this a good sign or a bad sign?

Is it because I pull downward and straight forward too strong ?

If anyone have encounter this during your PE journey, I’m happy to hear too.