This might be it? fingers crossed!!!!

So I was having some cramping yesterday like I usually do a couple of hours before AF decides to show up but I never started bleeding so last night I took a hpt and it came back with the faintest bfp ever. I am feeling hopeful right now but I am also so scared my body is already trying to get rid of a baby if i do have one. I have juvenile rheumathoid arthritis which is an autoimmune disease and my doctor told me it might affect my ability to stay pregnant. I am hoping this baby will stick around and wont be gone before it even has a chance to start.