first blood positive but low then second one negative?

sandra

friday been to dr with back pain,body aches quite bad,my breasts were very sore,nauseos but more in the morning hours,i know i was too early for pregnancy but the doc decide to fo a blood test as she thought i might be,anyways,saturday come positive but low,normal as if it was anything would have been super early,today went for another one and it was negative,back pain is back again but less,left pelvic side hurts and feels like pulling my leg as well,a bit nauseous not like all this days,discharge is normal a bit more than usual just like before af comes more clumsy and strethy,very bloated,buf in the same day today we had our fertility appointment ready to do another transfer,we were happy but ready for any good or bad answer,so,now my question is,has this happened to anyone?