Can a low dose pill work 8 years later if it did not work before. my records indicate that i only took it for 3 months and was switched back to 1/35.

Yes.: Female hormones wax and wane periodically (menstrual cycle) and can also change with time and thus sensitivity to OCP's can also change. I would like to know why the initial switch was done. If you were not getting adequate protection against pregnancy, then you can stick with the usual 1/35 or use a lower dose of estrogen combined with a stronger progesterone.

Maybe: It depends on what you mean by "did not work before" . and why it didn't work. If you are even few hours late with the low dose pill , your estrogen levels can drop to a level you can ovulate which can result in pregnancy.