This interrogate would be better bad if answered by a feminine since I seriously doubt any mannish can relate..
Answers: Long periods are considered irregular, and from what it sounds similar to it sounds pretty irregular to me ... you should recheck with that doctor of yours, but it sounds like he or she is taking things severely lightly. Try birth control pills, maybe.
I apologize, because I hold no experience in this, but I strongly recommend seeing a physician..
You didn't give your body time to make well after your first child. So it is still going thru changes just afford it time and it will come back to normal. If you be menstruating for more than 3 months and your doctor is calling it a "very long period," you distinctly need a new doctor!
There are fairly a few reasons for a long menses; in your situation, I would consider hormones a possible culprit - near two births so close together, your body may be having a tough time "re-adjusting" itself.
I would encourage you not to be afraid of finding out what's wrong. The solution could be a simple as 3 month course of birth control pills to take your hormones back in splash.
Another possibility might be an abnormally thickened uterine pool liner - the reason we have a extent is to shed the uterine lining - and, if that's the case, your doctor would execute a D&C to "clean things up." Don't worry: it's not life-threatening!
Please grasp yourself a new doctor! There is no reason for you to suffer or be afraid when a compassionate, compassionate physician can help you figure out the problem.