I’m pregnant, again..

So I am pregnant for the third time and I am honestly terrified. My oldest is going to be 3 in February and my youngest is 9 months. I’m supposed to be 6 weeks pregnant. I’m happy because I love both of my girls so much but I’m scared of not being able to give them the attention they need after my third one is born. Any one who is in a similar situations want to give me advice?