HELP.. When did i conceive?

[jessFREN122]

Hi, I am currently 10 weeks pregnant and the pregnancy was unplanned. I have polycystic ovaries syndrome(new diagnosis)  so have extremely irregular periods, often missing my period completely for the month. So last missed period gives me no indication as to when I fell pregnant. I am wondering if anyone can give advice as to which date they think is correct.
I had intercourse on December 16th and not again until the 2nd 4th 6th and 7th of January.

Today I am exactly 10weeks as dated by 2 different ultra sounds meaning my pregnancy started on the 22nd December.
I was being investigated for other conditions so was having multiple blood test and captured to exact day my hcg increased. On the 16th of Janurary my hcg was 2.8. On the 18th of January my hcg was 68.4 (two days apart).
I have read articles saying the first two weeks of your pregnancy you aren’t actually pregnant but is that only when you measure pregnancy from last missed period not ultra sound?
Also I have ready articles about timing of hcg production leaning towards the later dates being correct but hcg can be different for all pregnancies...

HELP!! Which dates add up?

[purple1234567]

What is the due date that you were given?  If you are ten weeks pregnant, it sounds like the conception date would be around the January 7th date.

The way a pregnancy is counted, is that your first two weeks you are technically not pregnant- basically they count from the last menstrual period, and 'normally' a woman is fertile about 14 days after that- so that's when you would conceive.  

It's very difficult to tell you the exact date of conception, because you don't always fertilize the egg the same day you have sex- sperm can 'live' for about 5 days- fertilization could occur anywhere in that time frame.  

Also, ultrasounds are not always 100% accurate with dating- the further along you are, the less accurate they are.  They can be off by weeks.  

A due date is just an estimate either way- they usually guess about a 2 week margin of error on both sides.  Also the HCG level has a very wide range to it, so you can't really tell how far along you are with that measurement.  

Are you concerned the due date is incorrect or do you have other concerns about the pregnancy you are trying to address?  

[jessFREN122]

No it’s not the due date, my GP seems to believe either the encounter from late December (was not a voluntary experience) or the encounters in early January with my partner of 5 years could be possible. I was just wondering with all of my information if it was possible to tell which date is accurate of conception.
I was leaning towards the early Janurary encounters with my partner but just wanted other people’s ideas.. makes it really hard because my last period isn’t an accurate measure as I often skip periods all together.

[jessFREN122]

Thank you also for your help!

[purple1234567]

I'd really lean more towards the January dates.  It's not possible to tell the exact date, beyond a shadow of a doubt, but it's much more likely January.  So sorry it's hard to determine all this, I'm sure this isn't an easy thing to walk through- let us know if we can do anything else for you!