Yes. My LMP was 7/16 and I went in for a blood test on 8/17 because I had not gotten my period and my hcg quant came back with a value of 1 miu/ml which means not pregnant. I went on with my life and started having sore boobs, fatigue, frequent urination, etc...around 8/26. I took an HPT on 9/4 and boom, pregnant. When I went in for my first OB appointment on 9/16 my doctor told me they were having problems with their machine giving off wrong numbers. I get my first ultrasound 10/14 so I can know exactly how far along I am, but according to him my blood test was a false negative. What's funny is my husband and I had an appointment with a fertility specialist set for Sept 1st but had to cancel it due to work conflicts. Looks like we don't need that anymore.