Am I feeling somewhat itchy/irritation down there because of tight pants?!

I've been wearing pants that are pretty tight in the crotch lately. They are dress pants I use for my new job because I can't use jeans. They used to fit a couple years ago but I've gained a couple pounds since then. I've been getting irritation down there. Just feels weird & a bit itchy, irritated. Also, I hadn't shaved (I normally keep up doing it once or twice a week). I hadn't done it in over a month so I just did that, hoping it will help.. Also put some baby oil on the area. I do not see any bumps or anything odd (and I had a yearly exam check-up by my dr just a month ago).. So I wouldn't think it's an std or something.. (I'm not sexually active). Has anyone ever felt itchy/weird down there from wearing pants with no room in crotch? lol I know it sounds rediculous but I want to make sure I don't have some weird problem.. and yes I'm going to get new dress pants, I couldn't afford to buy new ones til now.. thanks for input, ladies!