Birthday pregnancy announcement?

My period is 5 days late, my areolas are darkening, I cant sleep at night and im eating like a horse every other day despite never usually having any appetite. I dont know for sure yet but I think Im pregnant. I dont want to test yet because if its that BFP I dont think I can keep quiet for another four weeks!

My Partner's birthday is at the end of the month, I want to surprise him with a positive test but I already feel like crap! Im so exhausted all day and part of me just wants to tell him to pick up a test and some icecream on his way home from work.

Should I keep my mouth shut and do a fun little birthday suprise or just ask him to run some errands for me..