HSA Contribution for partial year

Hi,

 

I joined a company in September but my health insurance with that company will start Nov 1 so 2 months for 2019.  With my previous employer this year I did not have a HDHP and I did have an FSA which I used up before I left.

 

My HR rep is saying that I can still contribute the maximum, $3500.   They contribute on my behalf $750 however I am sure that will be prorated.  

 

Is the HR rep correct or incorrect?  I am paid weekly so if I subtract the $750 and prorate I can only contribute $45-$50 a week.  I am under 55.