Dating- sorry this is long

So my boyfriend and I have been dating for a year. Some things happened previously where he was cheating on my with one of our best friends( in the very beginning of the relationship)! We've fought about it multiple times but we've agreed that it's over and done with and we still want to be together. We talk every day and when we aren't together we're pretty much either on the phone with each other or texting. Lately though he's been coming up with excuses like he's gotta do laundry or he's on the phone with a bill company or he fell asleep or playing with the cat for an hour but I feel like he's lying to me sometimes. Am I over reacting or does anyone have any other solutions?? 😓😓😓