No Contact Rule Help!!!!!!!

My girlfriend of a little over five years and I broke up a month ago. We went the first month texting and emailing a lot and did not really miss each other because of it. She started dating another guy a few weeks ago, nothing serious just light fun and I honestly believe her when she told me that. I see it as seriously the "is my ex the one" card that she is playing. She is almost seeing if I am the one by seeing what else is out there; crazy I know but common I hear.

I finally emailed her a very heart felt email a week ago that I accepted the breakup and have decided not to be her fall back guy and that I am moving on and stopping the constant contact. It took her three days to text me saying she misses me and still loves me. My goal is to get her back, but I want her to come back on her own that way it will be for good and not me dragging her kicking and screaming. Honestly if we get back together we will get married. I have not given a lot of relationship specifics but trust me that is the case.

Do you guys think I should respond to her text about missing me and loving me even though it has not been a long time or should I keep the no contact rule going? It seems to be working... I do not want to play games because I want to marry this girl. She is 24 and recently graduated college and I will graduate next spring. I am in this for the long run and it looks like she might be too once she realizes it; she may realize she is better off without me and that is ok too because she will be happy and the relationship would not have worked out anyways.

Do I keep no contact going and make her miss me more or do I respond, break no contact, and speak with her light heartedly?

Respond to her and only say, "Do not contact me, for anything, unless you want to get back together."

Don't respond to any subsequent texts from her. Don't answer questions. Don't respond to anything that is not, "I want to get back together."