First of all, I hope you are #1: Not taking taking money from unsuspecting couples, and #2: Not the primary event photographer. That sounds harsh? Maybe. Not as harsh as a family who is not satisfied with their wedding "photography".
Photographers know how to use light and their equipment, have the experience and gear for the job, and more importantly the knowledge. You have "just started doing wedding photography"? With a point and shoot? Probably on the green auto button as well? Well, maybe not, this camera does have manual control, but the timbre of your question leads me to think you don't know much about the craft of photography in general. Certainly not enough yet to begin shooting weddings as a business or a side line.
Your camera is inadequate for event photography overall, but especially in dark rooms. The tiny sensor creates major difficulties that really will be hard to work around. Although the lens is f/2.8 on the wide end, it is getting pretty dark and slow at the tele end. The high ISO performance is pretty dismal, especially for wedding work, and not usable over ISO 400. So you are limited. Of course, we shot ISO 400 film for years at receptions and did fine.
You mention you are using an external flash. Are you bouncing and/or diffusing? If not, you need to be. Another technique that you need to learn is called dragging the shutter. The basics entail determining exposure for the background, using shutter speed to control ambient, and using aperture, manual flash, or compensation to control flash output and exposure on the subject. This requires manual exposure, and will avoid the deer in headlights look that auto flash often produces. This technique will work on your camera just the same as a SLR. Do you understand the connection between aperture and flash output? More research for you. A great place to read more about beginning wedding photography is photo.net. Go to the wedding and event forum, and click on the archives for newbies, also there are many forum posts on technique. Enough to keep you busy learning for months.
I highly suggest backing off from shooting any more weddings until you get the proper equipment, and a much better grasp on basic photography, and assist with an established photographer for some amount of time. These are once in a lifetime memories. Of course, having mediocre snapshots is better than having no pictures at all, and perhaps you are not really "doing" wedding photography, but are just snapping at friends' weddings. If so, disregard my dressing down in this post. If you *are* shooting for pay, you are asking for trouble in the future. Do you have photographer's liability insurance? You may want it when you get your first angry and disappointed bride who happens to have a lawyer involved. There is more to shooting weddings than pointing the camera and hoping the pictures are OK. Learn the stuff before starting.