I just got a roll developed in a lab. Couple frames at the beginning of the roll has issues on the long side. I am trying to figure out if my film was bad or if they screwed them up. (I don't think it was a light leak issue because the problem is in the long edge of multiple frames)
Pics taken on a Canon Ae1-p that did not have this problem before if it matters.
My guess is... shutter problem, like second curtain slow to close at the end. Sometimes old equipment can be slow and idiosyncratic when getting started or in cold temperature. Your camera may need maintenance (clean, lube, adjust).
Definitely check the negatives first for something similar, although as osullic pointed out, it's pretty rare that a lab will goof it up. The shutter is a good possibility as outlined in xiota's answer, but I also wouldn't rule out a light leak.
Frame 4 has the problem along the top and right side which, as the film is exposed, would translate to the bottom and left side. The film door on the AE-1 is hinged at the right, which means that if the door wasn't fully seated on the side where it opens, you could see something like this.
By frame 6, it looks like you were shooting somewhere else, so the door may have fully seated by the time you got there through pressure from handling or being put in a case.
