Are Apple's delivery estimates usually accurate?

I ordered a new Macbook Pro 13” on Wednesday 15th with an upgraded hardrive, it’s my first Mac and the original estimate (when I placed the order) was the 24th of June but I have since had an email informing me that it has been dipatched and the email, that arrived yesterday, then hinted at the 23rd. I then went into the track my shipment option and the current estimate is the 22nd. Do you think it will arrive this Wednesday (the 22nd) as I am excited to try and play around with my new Mac?
P.S the carrier is UPS if that makes a difference.