It sounds like you may have endometriosis from what you are describing. It is very painful and I am familiar since I have it. You can take pain killers (over-the-counter) but be careful if you are relying on them for a week+ since they cause stomach issues.
Yes, but do not take aspirin for a long period of time as it is known to cause liver problems in the long run. You might have to see the doctor though, if the pain persist for a long time