I was in boots and thought I'd get myself a BB cream whilst in there collecting a prescription.
As I'm browsing the make-up kiosts looking at the options I can see the female security guard(?) has left her position near the door to come to the make up isle and stood at the end of the isle watching me closely. After a couple of minutes she approaches me and says that due to coronavirus testers aren't available which is fine by me as I had no intention of opening any of the creams anyway 
She walks off back to the end of the isle and continues to watch me closely. I choose the one I want and make my way to the tills around the other end of the shop, I stop to pick up the dummy my daughter dropped and when i looked up the same employee is following me through the shop.
She only buggers off once she has seen me pay for my items.
I wanted to address her and ask what the issue was but as soon as she saw me leave the cashier she walked out of sight.
For context I'm 26, casually dressed (trainers and leggings) and have my little girl in the pram. I'm not a drug user and don't look scruffy (I hope!)
I phoned my DM to have a moan and ask whether it has ever happened to her, she said no despite the fact she regularly uses boots, Superdrug etc.
Today has reminded me of a separate incident where the same thing happened in a shoe shop, again where I was casually browsing to then buy.
I'm offended and embarrassed that this is the impression shop keepers get of me, what is the likely reason? Age? Pram? Trainers? 
It's absolutely not the case that this happens to everybody as confirmed by the multiple friends I've asked since. She looked at me and made a judgement.
WIBU to complain or is that overkill?