am I over reacting ?

Feeling a lot of anxiety and a tad bit crazy my bf and I are currently long distance ( it's temporary) and he owns a roofing company he hired a few months ago a new sales associate which I assumed was a man ( not sure why I just didn't think about it ) I finally visit last weekend and find out it's a woman but still had not met her yet just heard from his office assistant since they all work together. Now this new sales lady is apparently attractive and wears stilletoes to work and I don't care about other women or judging them it's just striking a weird cord with me that A.) she wears high high heels to work 1 not really being that professional of attire mainly Bc she's working in Roofing and climbing up on roofs (apparently she changes in to tennis shoes for that) B.) that I didn't hear about her right away just felt like he didn't want to mention anything about her and since I'm not there to see it or met her or be in the environment I feel more uncomfortable about that fact it could all just be innocent and my mind is taking me to crazy places but can you blame me ?? C.) they spend ALOT of time together like 7 am-8pm I know this job and industry is tough but his office is out of his home at the moment and it just makes everything THAT much more uncomfortable for me 
Am I over reacting or would this be a normal response for most women I havnt accused him just asked questions and it just seems like he dsn think it's a big deal he's met her husband but I havnt met her and I feel like he should of made it a point to first tell me about her and while I was there visiting made a point for me to met her :/ feel so anxious and uneasy about it all :(