It sounds like you are identifying ten day luteal phases, the last half of which is spotting. While spotting pre-menstrually can indicate low progesterone, as you noted, I would not be too concerned at this point. It can take months for your body to return to normal after discontinuing birth control pills. Since this is only your second cycle, it is very likely it is temporary.
I would, however, recommend not trying to conceive during this transitional time. I would be concerned that during this time of recovery from the pill, especially since your body is exhibiting signs of not yet having returned to normal hormonal balance, that you would be at higher risk for miscarriage. A rule of thumb is to wait 6 months after discontinuing the pill before pursuing pregnancy, but when you chart your cycles you might individualize that depending on what you observe. In your case, I would give it a few more months, and if the spotting does not resolve on its own during that time, I would consult a physician with specialized training in the treatment of such cycle irregularities. We have a list of them on our website at www.canfp.org Your medical appointment will be more productive if you have a record when you go off the signs your body has exhibited during those times. The doctor will find it more helpful in diagnosing and treating a problem if the charting you provide is standardized, for ease of interpretation. You can consult an NFP teacher to assist you in keeping such records.
Meanwhile, do not be too concerned—-and give your body some time to recover from the strong disruptive effect of oral contraceptives on normal function.
Sheila St. John