Confused on my weeks

So my lmp was 11/16/2015 my cycles were irregular, the last 3 months before I got pregnant was every 24 days. I haven't been to the doctor other than my blood test on the 7th of January they just drew my blood and sent me on my way. How do I find out how many weeks I am? Every website I go on gives me different days the app I use says 9w 4d, then the websites says 11wksor 10wks I'm so confused please someone help me out.