I need some advice...

Im married and we have a 3 month old little girl together. I found out about 1 week ago im pregnant and will probably have this baby before my daughter turns 1. The only one who knows so far is my mom. Im supposed to tell my husband on Christmas but part of me doesn't want to tell him yet... is that bad? When I was pregnant with my daughter his and i's sex life kinda took a crap and he was overly stressed and I was too. Right now everything is perfect and I dont want it to change. I just want to wait for a while longer like 15 weeks or something. Im extremely early pregnant and am only like 5 or 6 weeks pregnant but this mommy knows when her period is late.