when is the best time to test?

About 2 1/2 years ago, I was engaged and possibly pregnant (I will never know if I was). I had gone to the doctor because I was feeling symptoms that my body wasn't familiar with. I was the only one in the office that morning since I had to get the first appointment available. They took a urine test and  they directed me to a room.  I clearly hear the nurse tell another nurse, I think this is a positive, but the line is very faint. My heart skipped a beat of excitement when I heard her say that. The nurse whom she had asked said, I see it to but it's very faint, just take another one. I hear them taking amongst them and they said this once came out negative but she can possibly be testing to soon. The doctor approached them and tells them I will telll the patient to make an appointment with an obgyn. The doctor comes into my room and tells me the test is negative but I could be testing too soon. I made an appointment as directed by the doctor with my obgyn but my appointment was exactly one month after that appointment. 1 weeks later I started having extreme cramping and lower back pain, I quickly assumed, I'm not pregnant and I'm getting my period. The next day I was having the same pains but way stronger then the day before. My pains lasted for 4 days. In the 4th day towards the night, I drank tea to help me ease my paint like I'm normally do during my periods. In the middle of the night I started bleeding. It lasted 9 days.  I still went to the obgyn, she said it could have been a miscarriage and that I was suppose to come in right away into the urgent care or ER. She checked me and all she said was that normally after a certain time, they aren't able to know if I was pregnant but that she everything i told her sounded like a miscarriage. This is why I want to make sure that I do things right this time around and not get to excited.