I'm pregnant and I don't know how to tell my boyfriend.

I'm 19 and we have been together for over a year. I already have a son walking into this relationship and he adores him, however he has made it pretty clear he wouldn't know how to react or what he would do if he had his own. I noticed some changes that have been really throwing me off that I don't usually get before a period, ( super tired, breast hurt,headaches,back ache, and the bones around my pelvis started hurting) just really random things that I only expierenced with my last pregnancy but very deep into my pregnancy as well so I didn't think that much of it. Well I took a test the first day of my missed period just in case(negative), I thought whoooo that was a relief, then days passed one after the other..... I missed my entire period and checked today with another test and was watching it pass by and 1 pink line came up and I thought great!!! Then the other pink line faintly  came up and now I'm not sure what to do or even how to tell him, I've been through being young with a pregnancy before and I'm sure I'm capable of handling it but I don't know if he is and not sure at the same time if I am either, I'm honestly really scared.