need some help with this

so I'm 17 will be 18 in may I have a daughter who will be 1 on Feb 7th I live with her dad we're still together but I might be pregnant again we live with his grandma my period is suppose to start the 13th so ill test that day if it doesn't show if it comes back positive im not sure if I should give it to him as a Valentine's gift or if I should sit down and tell him I guess I don't know if I should tell him in an excited way or a serious way