I'm 43 And I Have 4 Kids, Just Today 24/12/15

I'm 43 and I have 4 kids, just today 24/12/15 I went to the Dr. because my period has not stopped since November 30th/2015, she checked me with a Vag.US and all seems to be ok so she ordered a few lab tests.
She gave me Duphaston 10mg BID to take for 14 days and once period is reestablished then on the 3rd day do the tests (FSH, T3, T4, and a few others) and come back with the results.
I've had my thyroid hormones out of wack before, and prolactin, and everything in between and I've taken meds for it, so I'm assuming that they are out of whack again (so they need some whack, lol), since the Vag.US showed nothing wrong.
My question is, is there a possibility of getting pregnant?
If there is, and since I've obviously lost track of ovulation because of the lengthy bleeding, how high is this possibility and when (if possible to know) could this happen?
I wasn't looking to get pregnant anymore, I'm very happy with my 4 beautiful monsters, but since I see a possibility I'd like to know my chances and if I can help increase those chances as well because I'd like to give my little son and his 3 sisters a new little brother. (As if I can guarantee the sex of the baby, yeah right!) Thank you doctors.
Merry X-mas and Happy New Year to all!!!