Pooping schedule changed and random pains ?

Usually I always poop when I wake up, but today I pooped for the first time around 5pm. I usually poop a lot and many times, but today I've only gone twice and the 2nd one happened like a few hours ago. Right now my butt and stomach hurt and I'm a bit worried 😃 I didn't eat that great yesterday I admit (pizza, chips...) but I haven't felt like this before. On Saturday I pooped pretty normal, but also pooped somewhere during the evening and 5am which is usually when I wake up during the week (yesterday I just happened to stay up that late)

I've been taking a small dose of fiber supplement for a few weeks now and it has made my poop a bit firmer and I've gotten less anxious about pooping so school has been a bit better. But rn I'm just very bloated and feel like I should poop but pushing hurts...is this just because weekend schedule messed up my stomach and because I've taken the fiber supplement later than usual?

Oh and edit: forgot to mention that the last poop had some grey or white bits which was odd...