Pregnant 4 months PP help!

I just had my baby girl on July 10 from a csection (had an emergency csection April 2018 with my son.) I’m exclusively breastfeeding but started my period a couple of months ago so my husband and I have been extremely careful.

I’m several days late from period so I took a test and it’s a strong pink. 😳

I’m freaking out because I know there’s a risk of uterine rupture.

I just need some positive stories that this can be okay. I’m so scared.