Hcg blood test negative now positive days later

Glo

Hello all. I did my 2nd Iui on the 22nd of July. I tested after my 14 days and was getting negatives I requested a blood test to confirm. I took Hcg blood test on 8/6/2020 results were 1.3 negative. Today 8/11/2020 I go in for my baseline and bloodwork to start my next Iui cycle and my Hcg blood test is now 13.6 I’m so confused. So I was told not to start Leterzole and to come back for blood work again on 8/13