Well, seeing as though you are in your 40's...it's quite possible that you're experiencing some perimenopausal symptoms. I'm 43, and my monthly cycles are all over the map...sometimes early, sometimes late, sometimes heavy, sometimes light...it's a crapshoot every month. I never know what or when it's coming. On the otherhand, spotting between periods can also be a sign of fibroids, which generally do not pose a cause for concern. But if you're having other symptoms, such as pain...then I suggest you see a doctor. Are there any low-cost clinics in your area?