That sounds very familiar to me!!
First, I think 3 months is WAY too early to start any solds, even cereal. You should wait.
Getting 4-5 oz per pumping session sounds about normal. (FWIW, that's generally about how much I get)
There is a lot of good pumping info on
www.kellymom.com Here's my experience:
I've been pumping since DD was 8 weeks old when I went back to work. She is now 7 mos. When I first went back to work, I pumped every 2 hours. I'm not sure what your schedule is like, but if it is possible for you, I'd highly recommend that! Also, if you're the one dropping her off at daycare, leave a little early and feed her right before you leave, so she's "topped off". Tou could also ask her sitters to try not to feed her after a certain time. (I have always requested that my DD isn't fed within 1 hour of my return. So most days she's starting when I get off work, but its better for me to BF).
If you can't pump every 2 hours, the absolute longest you should go without pumping is 3 hours.
Also try to add some pumping sessions in when you're home with baby....for example, I always pump just after I put her to bed at night. Also, throw in as much pumping as you can on the weekends - if you're home and its feesible, try to pump after each feeding.
This will help you start to build up a supply, and you may be able to freeze some of the extra. Or at the very least, it will give you a few extra bags to use during the week.
Also, if she is going to a daycare, I'd recommend packaging her milk in 2-3 oz bags/bottles. The daycares in my state are required by law to throw away any breastmilk or formula not finished in a single feeding. So if your LO isn't taking all 6 oz...but say 5 oz, you're losing an ounce a feed...which if she eats 5 times while you're at work is a full bottle. I just hate the thought of anyone's breastmilk getting thrown away!
Hang in there! When you go to your Pedi for LO's 4 month checkup, be sure to tell her your concerns - be sure to let them know if it is your intention to continue breastfeeding. Some Drs will just say supplement right away. There are lots of other things you can try to stimulate your supply. Ask about solids then (My Dr advised us to start small amounts of cereal just after 4 mos)
Finally (wow this is getting long) I take Fenugreek to help stimulate my supply. It is an herb that you can take while BF and it doesn't affect the milk. The only side effect is that you can smell a little like Maple Syrup. My hubby tells me it makes him hungry for pancakes

I've heard there are teas out there too, but from what I've read different things work for different people.
If you've actually read this long - Thanks!

If you have any more questions, feel free to email me at
kell0613@hotmail.com Keep at it, you're doing a great job!!