Should I be concerned

My boyfriend and I have been together 7/8 months. His ex girlfriends friend followed me on Instagram a few months ago and when I realized who it was I removed her. Now she is on my other social media page “viewing my profile”. I’ve said something to my boyfriend but he says he has no communication with either one of them but it’s still weird. I wrote the friend and asked her if why she was following me on everything and she just says she “saw me while scrolling” … but I don’t know why they would still be creeping on me as long as we’ve been together.