So my last period was 24th of August and it went till the 2nd of Septe…

So my last period was 24th of August and it went till the 2nd of September. I had sex on the 1st and 29th of September. I went to the doctor on Friday (27/11) and the pee test came back negative then it went positive then back to negative within a minute or 2. It's normal for me to go a month without my period. I told the doctor that and she said that I could have my period one month then sometime in the next month I ovulate.... I did a test yesterday (28/11) and it came back positive I've taken a blood test but also the other ones I've done has come back negative. Is this normal?