Sisters pregnant after my miscarriage

In march of this year I miscarried at 6 weeks. The day after I found out at roughly 4 weeks I started spotting and just figured maybe the test was wrong. But then tested positive again a week later. The day after that test I started cramping heavy, and bleeding, and I went to my dr. She ran some tests and things and discovered that yes I was pregnant, but that I had begun to miscarry. I'm a mom of Two, one is 8 and the other is 18 months. I am a non traditional student...and stay at home mom...I passed my baby on campus and it was literally the worst thing ever in my life! I had legit labor pains, and had to leave class...it hurt a lot...physically and emotionally!

I was on birthcontrol and I was taking it right. We were not being stupid about it, I was breast feeding...I honesty believed I couldn't get pregnant because I was doing really well with it all. I was due October 31st. And would have had a repeat c-section on the 28th of the month like my other babies! I would have been so happy!!!!

2 weeks ago my sister called and announced that she's pregnant. She's 32, with 1 16/17 year old, 2 13/14 year olds, a 6 year old that isn't even hers...a single mom, no steady job, living on barely any money, her car is breaking down every 5 seconds...she has NO business having more babies! Don't get me wrong I'm so happy for her, but I'm so jealous and angry, and hurting! I should be having my own in 6 weeks, I should be planning delivery, and going to drs appointments, and making room in my house, and getting baby things...and my husband refuses to even consider trying...I'm married!!!! I did EVERYTHING right! Everything! I married my high school sweet heart! I only had sex with him on our wedding night, my kids have the same parents, almost 12 years together now! I'm doing well financially, I'm almost done with my degree, everything is perfect! I have the house, the 2 kids boy and girl, the husband, the white picket fence...I know it should be enough, but I'm missing out on something I lost and my sister doesn't need it, and is getting it anyway...I know how I feel about it is wrong...I'm happy for her...but I'm so incredibly jealous and I can't even talk to her...