If a shy girl giggles at you?

So after a few days of not seeing this girl, I went up to her to say hi. After that I asked her if she missed me, she got all serious (I don't know if she was acting) and said NO. I was like "OK, fine" turned around and started walking away and she started giggling, then I looked back and had this really wide smile on her face. Is she just playing with my head? Sometimes I feel like she likes me, but its hard to tell since she is shy. if others ask her she will say "of course I did" but she is way too blunt with me haha.
If a shy girl giggles at you?
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