Am I pregnant?

Ok I had my period a month ago,I've been feeling nauseous,cramps,back pain and some others pregnancy symptoms,I have never been late on my period but now I'm missing my period by 3 days and this morning I took a clearblue digital test and it says I was pregnant by 1-2 weeks, I went to the doctor and they said it came back negative,they still did a blood test and say to come back in a week, please help, could I be pregnant? I've been trying for monthssss