I agree with the previous posters...pregnancy is not likely. You mentioned that you are both very paranoid...I think that is showing here and she is being hyper-aware of anything that might suggest a pregnancy (and will not notice anything that suggests she isn't). Her mind-set could even cause her period to be delayed so be prepared :)
Continue to use condoms, with a spermicide, and encourage her to look into also getting another type to birth control (the pill, diaphragm) as Clysta mentioned, nothing is 100% effective and using two types decreases your chances of an unplanned pregnancy even more.
clysta said it best
if you didnt ejaculate than there is no possiblity of any pregnancy
What she felt wasn't pregnancy. It's not possible. Namely because after 2 days, she wouldn't even be pregnant yet. What has to happen first is that she needs to be ovulating. If she is, and you ejaculate in her (or in the unlikely chance your contraceptive fails) sperm meets the egg. After around 7-14 days it will implant in the uterus. Then it starts to release hormones and only then will you notice anything related to pregnancy.
The far more likely case is that it's due to having sex. The first time a female does she might experience bleeding. Usually it's due to friction and irritation. This is also the likely cause of the cramping as well. Food cravings happen pregnant or not, and mean nothing. You don't even need to be female to have them, so her feeling that isn't really important. Neither of you have anything to worry about. You can have her take a pregnancy test in 2 weeks if that might make you feel better. It would also be good for her to look into getting on birth control as well. This will just give added protection, since no method is 100%.