I want to surprise my family, Any tips on to do so?

I'm currently 18, and I've decided I want a baby. I understand it is difficult to raise a child, especially doing it by yourself. I'm going to be 19, and be 20 when I give birth. I decided to be artificially inseminated by a sperm donor. Reason why I'm not telling them right away is because I'll be living in another state, and won't be able to visit until around Christmas time, which I'll be 25 weeks on Christmas Eve. So a christmas theme is ideal, and thank you for all your suggestions. :) Here I'll give you timeline. -July 16th 2019: I'll be artificially inseminated -July 30th 2019: 4wks: Positive Pregnancy (maybe) -August 27th 2019: 8wks -September 24th 2019: 12wks -October 22nd 2019: 16wks -November 28th 2019: 22wks -December 24th 2019: 25wks (when I plan on telling them)