Abortion after birth

I gave birth to a beautiful baby boy almost a year ago and starting having my period about 5 months after he was born even though I’m still breastfeeding. My period is 7 days late and I’ve actually already had a miscarriage since giving birth. I got pregnant with my son on the pill and I’m taking Mirena but somehow both have messed up. I’m worried that I am pregnant right now but having another child isn’t in the books financially or otherwise. Is it selfish to think of aborting if I am pregnant? Itsnot that I don’t want another child someday. I just want to make sure I can give my kids the best life possible