Ex texted me on my birthday

So I’ve been following the no contact rule and it’ll be over in about 5 days. Thing is that my ex texted me on my birthday wishing me a happy birthday. Short, simple, standard text. I don’t know if I should reply with a short answer like “thanks” or if I should continue no contact for a few more days and ignore her text.

She broke up with me and as silly as it sounds, I don’t want bad blood between us by me not at least responding to her. However, I know if I break NC and respond, things won’t change for us. I’m not sure what to do!!! I just don’t want to come off as rude even though I know I don’t owe her anything.

Our break up was very odd. We’d been dating for about 2 years, living together and she said that we should break up. Thankfully we only had about 3 months left on the lease but those 3 months were hard. My emotions went through a range and her behavior was odd too. Sometimes she’d act like we were still in a relationship, blowing kisses at me, touching me, etc. Twice we fell asleep together and once we had sex. Nothing changed between us still and over the summer she would ask me if I wanted to kiss her. I don’t know why she did this, but finally we’ve had some REAL time away from each other and I initiated NC. I’m now nearing the end of my NC and I’m still not sure if I want to contact her. Thinking of her or running into her gives me anxiety.

Any help would be appreciated, and I’d love to hear other people’s stories too.