Have feelings for my ex?

She broke up with me a month ago very suddenly.We had been dating 5 months and had many good times but also a few arguments leading her to be disappointed in us and she found some bum who was willing to listen to her problems. All of her friends love me and are shocked she has left me being that im a genuinely nice guy and treated her well and now she may be seeing this other guy at work. I ended up deleting her facebook and deleting all our pictures. But yesterday made me second guess myself. I ran into her at work and i asked her how she was feeling. She explained to me she was going home early and she wasn't feeling well she said i know how she is when shes sick because i use to take care of very well when she was sick and i said yes i remember. Her eyes were teary and her voice was soft and i told her to have a nice vacation. I was very kind smiley and bubbly. Shortly after though i got a pain in my stomach like i felt there was something there and maybe i should shoot her a text while shes on vacation this upcoming week. I am strong and prepared to move forward i just feel like this girl is very special to me even though for some reason even though she did me wrong. What would you do in my shoes? I really do care for her. thanks guys!