Something has to be wrong

18 and 4 miscarrages. Going to get tests done after the first. Scared its major. Feel like crap cause there's a 10 month old, a one month old and one who's due in June. Everyone keeps saying we need more grand babys and I just want to cry. I've had two this year just 6 weeks apart. I feel worthless. No one this young should have this mint miscarriages.