Mom got pregnant during perimenopause

Hi my mom is 48 and I’m just wondering if anyone about the same age as dealt with irregular periods and thought was in the perimenopause and then became pregnant ?

When my periods started to become irregular I was about 42 and in the beginning I took a lot of pregnancy tests just to put my mind at ease I wanted no surprises my periods have been all over the place in the last few years from skipping a month to a normal cycle to being a couple of weeks late it’s really annoying hard to plan anything when you just don’t know when your getting it! And if your in Peri be careful because you can get pregnant