Increasing amount of beauty marks/ freckles?

I used to have maybe a total of 5 of these spots on my body and within the past month or so about 20-25 more of them have appeared on my upper chest/ neck, arms and back. I’m not too worried about it - really just want to know the cause of it and if theirs anything I can do to stop them (I can see faint ones forming). My mom said they’re from the sun but I’ve been working inside all summer and barely seen it. they’re all flat and round but my bf is concerned and thinks I should see a doctor. But before I go I wanna make sure this is something I should actually be worried about - I googled it and of course it jumps straight to cancer.