Switched to whole milk

I know most people don’t switch until 1 year, but we have 10 days left until my sons first bday and honestly he was basically refusing his formula. I did a week and a half of mixing formula and whole milk and he did fine. He loves milk so there’s no issue. He’s been having about 8-10 oz of milk a day and water throughout the day. Is it normal for his poops to change? He has had 2 days where his first poop is little balls then it’s more so a clump of mushy poop. He doesn’t ever seem like he is straining or in pain. I’m a FTM so I’m not sure. I also know some people choose to not do cows milk, but we are so I respect everyone else’s decision so please respect mine. That’s not to say we won’t explore almond milk or other types as well. For now, it’s cows milk. I’m just looking for some advice. Thanks everyone!