One more time..please help!?!

One more time..please help!?

Please help...clarifying my previous question!?
I recently posted a question in regards to a 10 week ultrasound and the accuracy of it. However, I was not clear enough and some people said to add more detail to my question. My question is how accurate is the 10 week ultrasound as far as predicting due dates. I know that the early ultrasounds are accurate within a week or so, but I am wondering if it is at all possible that it's off by a month? I also had one at 20 weeks and it was also accurate to what I thought my due date is...Please answer only if you have been through a pregnancy. Also, I had an ultrasound at what I believe to be 6 weeks pregnant...it coincides with all other pictures I have seen while researching 6 week ultrasound photos. So, anyone willing to help me? I'm 34 weeks now (and my latest u/s which was on Friday measured me at 33 weeks), so I'm still right on track. There is a question in regards to who the father is. My belief or someone who I seen a month earlier?

the techs really know what they are doing. As long as you aren't having a very large baby then they should be right on track. did they give you the weight they think the baby is at? as long as the weight matches up with where they think your baby is in months you should be good.