Girls, Need your opinion on my friend?

Just confused right now and wanted some opinion to think better here.

I have a girl best friend and we've been friends since childhood. I never had any other feelings for her, except friendship and so did she. We shared all secrets about everything, even all relationships.

We both are single for more than a year now and few months back, we both were drunk at her place and decided to "experiment" together.

We both made it clear, our feelings won't change and we will be same like always.

So we did it, and like it a lot. So we started having sex frequently whenever we craved for it.

But recently, I started noticing something different in her behaviour. I don't know if it just my thinking or something actually changed.

But she started to act different, a bit more than usual. Like back then, whenever I went on date and told her about it, she was like saying good luck or something like that, something supportive.

She still does, but now I can feel her voice tone gets a bit disappointed whenever I mentioned about dating.

Just named your opinion, am I over thinking?

Girls, Need your opinion on my friend?
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