Hey, Im 17 and I just had my baby in december. When I found out I was pregnant I was 16. It never is easy telling your parents, they most likely will be mad! But when they see your baby the day he/she is born they will love your baby to pieces! I got married at 16 and my husband was 18. Now im 17 he is 19, and it is a great life! I felt the same way you felt! How am I going to do this? But as soon as your baby is born your motherly instincts kick in, all you want to do is change diapers and feed your baby. You feel as if you knew this information forever. My advice to you is stay stress free and happy! Your emotions effects how your baby will act when it is born, I was really stressed when I was pregnant and my baby came out with colic.
I know what you are going through although I got pregnant at 18. It was still difficult to let my mom know. It all depends on your relationship with her. I was scared because my mom usually gets very mad over things so I text her and let her know and she just asked if i was keeping the baby i said yes. After we just talked face to face about everything and she supported me. So sooner or later you have to tell her and I would say sooner is better she doesnt want to be the last person to know she should be one of the firsts she will appreciate the honesty. Also I know you said you guys are financially fit but no matter what you will go through hardships I wish you two the best because you both really need eachothers support. My son is 7 months now.