Until you have a simple conversation with your employer, you are likely getting worked up over what could happen. I speak from experience, as I was at one point in the same boat as you.
I work for a very large company (1B+ annual revenue) they have entire advertising and marketing department. We use multiple ad agencies and they are always hiring different photographers for projects.
Occasionally I would be asked to shoot an event, because that event had no budget. I helped out when I could, and people liked my work. Photos would be used in internal communications and a couple times in externals. My hope was to build some good will to get other paid work from the company. Well that really didn't happen, they just kept asking for me to work for free. Now I did do the work on Company time, I got my salary, but I was using my own gear.
Finally one day they asked me to do a shoot, and I decided to explain the situation to them. I let them know I am happy to help represent our Company in the best light possible by providing them with great photos at these events, and my boss has been supportive of giving me the time to do so, but the time needed to do this work outside of work hours does affect my time with my family, and I am now doing photography as a business, as such, I really need to start charging.
Low and behold, the answer was, "I understand, we don't have a lot of budget, but let me see what I can do." sure enough they were able to offer me compensation for my work, and they have paid me for a few additional shoot since. I don't get many shoot with them, because they have specific photographers they use. That said, when they do need work from me, I do get paid.
The point is, just ask. and like anything else in business be respectful, and let them know what is bothering you about it and see what they say. If they tell you to suck it up and it is your job, then get them to provide you with the necessary gear. (maybe your camera is in the shop for repairs) *wink*.
Hope this helps