My kid was only 3 weeks + 1 day early (almost 37 wks), but also only a drop over 4 lbs. No delays or PT/OT thus far, age 4.
Don't worry so much about it, but don't hesitate to get early intervention if any milestones are missed. It can help that.
Poop ends, at some point, or at least consolidates to 1-2 a day
At 1 month, there are so few milestones, but you can absolutely get an evaluation if you have any concern. You dn't need pediatrician referral. I would definitely wait a bit before you get concerned. hang in there, and congrats on the new member of your family!
Hang in there.