I wouldn't recommend fixing with formula. Just give whatever you can express and than make separate bottle of formula. My mum only managed to breastfeed us until about 2 or 3 months the most. My lo is 11 months and we still breastfeeding.
Nothing will happen, your baby may get a bit constipated at first or may even turn his nose up at different milk. While your still producing try to combination feed for a week or so (breast sometimes and then bottle another) it will make the transition easier for both of you.
Is it going to cause him to spit it up alot or not really? Cause he's used to not getting enough from me most days I try to just feed him more often with what I can but then when he can get enough he usually over eats and spits up.
There are ways you can help yourself produce more milk :) expressing May not get much out because your body only responds to your babies saliva! And the best way to up your supply is to feed feed feed straight from breast, have lots of skin to skin with baby and eat lots of oats :) as long as your baby isn't losing masses of weight and is having plenty of wet and dirty nappies then you're doing brilliant :)
Sounds like you've gotten some good advice above. Talk with your baby's pediatrician if you are thinking of going to formula. I would highly recommend seeking out nursing help first! My supply always sent down when I'd get my period - how old is your baby?
He's 2 weeks old. The only way I produce enough is if I only feed from one for 6+ hours then switch
I nursed my kids about 10/15 min on each side. So a total of 20-30 min of straight nursing. Sometimes you may not feel 'full' or know how much the baby is consuming - that's a tough part of nursing. If you hear a clicking - that's the baby swallowing - you know they're getting something. Also - consider the 'output' of your baby (wet diapers and messy diapers). That's a good way to tell how much and if the baby is consuming enough.