Yes and be thankful that you don't have cramps. Lucky you.
If you have a normal period with normal flow you are not pregnant
No, not having cramps is normal and lucky. If your haveing a normal flow you aren't pregnant.
I'm not entirely sure where you're going with this question, but if you've had a normal period with normal flow since your last intercourse you are not pregnant.
No, you can have cramps and spotting at the time for your first period after conception but not full menstrual flow.
As long as you are having normal period flow, the absence of cramping just means you're lucky.
The absence of painful menstrual flow is just normal menstruation - menstrual cramps are common but not a normal part of healthy menstruation at all. If you're missing your period all together then there can be a number of reasons, if you go more than 3 months without a period see your doctor.
No, you cannot have periods after you are pregnant. You can have minor vaginal bleeding but it is not a full period flow.
No.
Then it's a normal period, nothing to worry about.
Then that's normal.
Yes, if you have cramps but no menstrual flow, you can be pregnant.
If your flow was light like this then you shouldn't have been using tampons - without sufficient flow tampons will have more of a drying effect which can cause discomfort, increased cramps, and puts you at higher risk of toxic shock syndrome. The back pain and cramps may very well be normal menstrual cramps, or increased cramps as a result of tampon misuse, but there may be another problem - if this continues talk to your doctor so they can investigate to make sure everything is okay.