at what point is enough enough

I'm posting anonymously because first off I have been through a lot and have shared some on here and I don't want to be judged or labeled or badgered. I just need some advice for something that could seriously seriously huge discussion for me and my family.

I have miscarried and then had a set of two beautiful rainbow babies, this made me a mother of 5. We talked here and there about one more but so much has happened that I don't think it would be good for us. So here I am a few days late for my period. I have a number of health issues that made it difficult for us to conceive so it really never occured to us that we could on our own. abortion isn't an option at all so I guess I am asking at what point do you decide to have a baby but let it go to someone else. Let your baby that you carried for 9 months go to call some else mommy just because things are too hard right at the time it was born. Or is this something I'm thinking to hasty? I know I need to find out if I am indeed pregnant first and there needs to be a convo with my SO but there is just so much I have already thought of and I am scared to death. thanks for reading sorry so long