Should I let it go or have a right to be mad?

So today my bf of 4 years was supposed to be getting his tattoo done today. He played basketball with his friends in the morning and texting me around 1 saying that the tattoo guy said to go around 5pm. So then that was the last text I got from him and he left me on read until like around 8pm I had texted him asking if we are still going hiking tomorrow with friends early and what time are we going. He said that he would ask and then he left me on read once again for another 3 hours. Now I was like okay I understand he’s probably still getting his tattoo so he’s not able to text rn. But then I started thinking that his last half forearm tattoo only took 4 hour so this half that he’s getting done should’ve only took 4-5 hours meaning he should’ve been done like around 9 or 10pm at the latest right? But still no word from him so I decided to text again and say damm your still getting the tattoo done?? until about 1am he finally answered!! Saying “No I ended up not going because he took too long to reply” and I was like are you serious! All these hours I was thinking he was getting the tattoo done but he was out with his “friends”. Something seems fishy to me but idk if I’m just overthinking it. Usually he would say something but sometimes he’s Horrible at communicating. Like I honestly am just really annoyed because I know for a fact he wasn’t busy busy all those hours to simply not be able to say that he wasn’t going and was going to just hang out with friends. He said “I forgot to tell you I’m sorry” like how do you forget when your most likely on your phone.( he’s literally always on his phone, even when he’s out with me) He had from 2pm to 1am to say something! I don’t what to think but I have a bad feeling idk if it’s because I’m going to start my period soon or if something is up🥴 should I still be mad and not see him tomorrow because I honestly really don’t feel like seeing him at the moment or should I drop it and just move on with it hoping he’d understand.