Relationship advice

So just needed some advice on how to handle a situation. My husband is attending a University despite his age... 38 to be exact. Proud of him for accomplishing so much including going back to school at his age. Anyway I have a bit of trust issues. Yes I admit it. Him being around young college females. Its not that I don't trust him... I dont trust women. Anyway all I asked is if he ever needed females numbers due to school or work for related to let me know so I am not caught off guard and out of respect. I guess he said I never asked him that. Whatever so yesterday he was sending this long text to someone. I happen to ask who he was texting. He said some girl from his class that was asking him about an assignment. Of course I made a big deal about it because he says he talks to no one at school and the fact I had one request and that was to to let me know. He totally disregarded what I asked. He didn't understand why I was making a big deal about it. Then when I looked at his phone he had deleted all the messages between them. He told me it was because he didn't want me to pick at everything that was exchanged and it was only about school. He says I always find a way to over analyze things plus he had no need to talk to her anymore. The project they were assigned together is over. I didnt even know he had an assignment with some female. He never tells me much about school or work. I know I can be high strung but his actions don't help. Am I over acting or is deleting the texts seem odd? It makes me so bad that he thinks I am making a big deal about nothing.