I really want to go back to work but I have one thing holding me back. I want to suppliment with formula while Im at work and Im not sure if I can do that without pumping at work. Id really like to go without having to pump because I don't have a place at work to do so nor the time. Will my milk dry up if I do this? I'll only be working on the weekends 8 hours both days... can I do this or should I just stay home if I can?
How old is your baby? If nursing is WELL established, you can probably pull this off. I would research virgin gut a little and see if you don't change your mind about pupming. I was working at an outdoor theatre this summer and pumped with my Avent Isis in my car during a slow part of the play each night (my son was 4-5 months). If you will only be gone two days you might be able to pump enough during the week to supplement while you are at work.
Also, be prepared for reverse cycling it is often a good way to keep your supply regular.
Of course, you'll be able to leave formula for your child instead of breastmilk. I am concerned about the fullness of your breasts by the end of the day, though. Since it's only two days a week, and from your post, it sounds like you'll be nursing the rest of the week, your supply probably will remain the same on the weekend as it does during the week.
You'll need to find a way to remove some milk from your breasts at least a time or two each day. You can use a pump, of course, but there are other options.
You can express your breast milk manually, see instructions here. http://www.lactationinstitute.org/MANUALEX.html It can take practice to master this, so you might want to try it at home, or even in the shower.
This technique is good because you can express just enough milk so that you're not engorged, and you don't have to worry about keeping it. You can express the milk into a cup, bowl, sink, or whatever's available.
You can take a few minutes to do this only when you feel like you need to, not on a schedule.
If you decide to go back to work, know the signs and symptoms of plugged ducts and mastitis, so you know what's happening, and what to do about it, just in case it happens. Plugged ducts are much more likely to happen when you're not emptying your breasts as often as they're used to be emptied. Read about it here: http://www.lalecheleague.org/FAQ/mastitis.html
Only you can make the decision that's best for you and your family. If you want to try it, see how it goes, then re-evaluate your plans for the next weekend. It will all work out in the end. :-)