When is my due date ??!!!

With Rory I knew exactly when she was due and even though in the last month my doctor moved my due date earlier 4 days I still knew when she had been conceived. With this one who is known as TBD I have no idea. My last period (sorry boys ) was December 21 ( I was and am still breastfeeding so everything was screwy) which would have her due Sept 27th. But the first ultrasound we had said Oct 10th the second a week later Oct 19 and the third 1 week after that Oct 16 . (I had a lot of ultrasounds because of my progesterone being so low) Oh and dont even ask me when we had sex because I had finally lost the baby weight, Rory was sleeping through the night so ALL of January was Sex Fest 08. And then there was what Marc called pity sex when he didnt get in to the graduate program he wanted so who knows. Anyway it didnt bother me that I didnt know until this week I really want to know am I 24 or 25 weeks pregnant??? I know it is just a weeks difference but mentally it would mean so much .