what's going on with my body?

Alicen • 22 years old. Married to my best friend on 06/13/15. Had our princess on 03/04/2016. Angel baby 11/23/2016. 4 fur babes!
Long story short. I have an 11 month old daughter whom we got pregnant on the first try with. Me and my husband were going to wait and till she was a-year-old to try again for number two. Well in November I was seven days late and when I did get my period It was very heavy and painful. Decided to take a test to confirm my fears and it came out positive. I got all of the blood work done and they confirmed that I was having an early miscarriage I was no longer than a month pregnant. Although we were trying I was completely devastated. On December 1 I had my annual check up and the doctor had gave me the OK to start trying for baby number two so we did. In December I was four days late so I decided to take an $.88 test from Walmart and it had came back negative but I wasn't giving up hope I did end up receiving my period. Little discouraged but not to much. In January I was also 4 day late so I decided to test again not wanting to spend much money I just got the 88 cent test at Walmart. Again it was negative. I had my period 01.14-01.20. On Jan 25 I wasn't feeling too well so much for the hell of it I went and bought an $.88 test and took it and I got a faint positive! So of course I ran back to Walmart I had bought a first response test and I went to head and did it that night and got my big fat positive I was so excited, well everyone always says to test with your first morning urine. So when I woke up the next morning I had tested with another first response and it came back negative.  I was a bit confused so I decided to wait four days to retest I have got to first response test and $.88 test and early pregnancy test when ahead and did all of them and they all came back negative. I'm not too sure what to think I'm finally feeling defeated I don't know what's going on with my body. My OB once me to wait until February 17 to come in and get an ultrasound I'm not too sure why she does not want to do bloodwork first. Has anyone else ever been through this?