Is It Possible To Miscarry Before I've Even Missed A

Is it possible to miscarry before I've even missed a period? Is there anything I can do to save it even though I don't know for sure if I'm even pregnant? We've been trying for about a year now and every few months I'll get this morning sickness feeling and over tiredness gasping for breath from just doing the dishes having to go sit down and rest in the middle of it. I'm so sure each time it's for real but when it's time for my period to show up, it still comes and I feel fine again! I don't know what to do anymore.