Is my GF telling the truth or cheating on me?

Hi so here is my problem guys: I have been going out with my GF for about a yr now and everything has been going well - and just recently we went on a holiday together and had a wonderful time. However some things concern me: -Recently on sat night we both went out together in separate cars (as we don’t live together) to a bday and we all stayed till around 2am and left presuming we would both go home. She said message me when you get home in which I did but got no response. I fall asleep thinking she was already asleep but then wake up in the morning to find she has gone somewhere else to pick up/chat to her two friends who were out apparently.. and gets home 5:45am... The message also said that to say I was with her with her parents ask when i come over the next day.. So it makes me think it all sounds a bit dishonest like she was only telling me so that she could cover her parents off. To myself itcomes across as dishonest and loses my trust as she tells me after the fact. Not that i need to know where she is 24/7 but if u your going somewhere then atleast tell me if the original plan was your expected to go home. Sigh it makes me feel like she is lying or possibly cheating on me.. thoughts? One last thing she still messages her ex alot... or am I being worried for nothing?

Yep Joey, the issue is you were asked to cover for her to her parents when in fact you weren't even with her. After 12 months, you should be seeing things or know certain things which tell you what sort of a person your GF is. You used the words dishonest and trust, cheating. If someone asks to receive a message then it's good manners to reply when it comes through but if your GF asked for message then it's an expectation that she reply. You wouldn't be on this forum if you thought it was all ok but it's your gut telling you it's not all ok regardless if she's cheating, lying or not. This episode in your relationship could be telling you what to expect down the track if you remain together and develop into a serious couple.