I had my period a week later.

If you had your period most likely you are not pregnant. With that said, you will have to see if the next period comes as expected. If not, take a test using first morning urine and follow the directions carefully.

I've been having breast tenderness this week and the sex was the second weekend of October

When is your next period due?

My next period should be around the 24th of November

You will have to wait to see if that period comes or not.