First of all, congratulations!
Unfortunately having a terrible headache like this can really put a damper on your joy and excitement. While I have not experienced this personally, I am an L&D nurse and have had several pts with spinal headaches after getting an epidural. A week does seem a little late for initial onset of a spinal headache, but I supppose not impossible. The surefire way to tell a spinal headache from any other kind is -- a spinal headache will disappear if you lay completely flat in bed. Any elevation of your head will cause it to return. If this is not the case with your headache, then it is not spinal related and you should follow up with your health care provider.
When pts get spinal headaches at the hospital the anesthesiologists initally prescribe what was reccommended to you, fluids, meds, caffine, and laying flat (all of which is fine when you are breastfeeding, especially on such a short term basis). If the headache has not resolved in a couple days they will discuss the blood patch as described by previous posters. The blood patch is not necessary, the leak of spinal fluid will resolve on its own eventually (time varies from person to person), but it would expedite the recovery.
Good luck with everything, hope you feel better soon.