I have no idea what's going on

The only real life woman who I discuss my pregnancy stuff with is E. She has dealt with difficulty getting pregnant and miscarriage, so she understands this kind of stuff. She is busy with her baby now, but she definitely tries to find time to talk and listen and commiserate. So, I told her about the BFP and then the BFN. She called to ask how I was doing with all this information, and I said I was feeling okay. I was mostly concerned with how this is going to delay the IVF and how that sucked. I knew that there was a chance of delay when we decided to ttc this month, but I figured it would be for more than a chemical.

Then I got to talking about how I hadn't started bleeding yet and how today was 18 dpo. I also have been taking my bbt the past few days and today my temp was the same as yesterday, so I knew I wouldn't be bleeding again today. I told her that if I didn't bleed by Tuesday I would still go in for that HCG blood test so we could figure out what was going on. She thought that was a good idea. We talked about my symptoms (none, really except my b00bs are ever-so-slightly sore) and she asked if there is any way I thought I could be pregnant. I said that I guess the test could have been wrong or something. Then her baby woke up and she hung up.

Then T and I started talking about it more. It was weird that it was 18 dpo and I had a negative pregnancy test but no bleeding. It was weird that I had a negative pregnancy test and my temp was still above the 'cover line'. This whole situation was weird. He asked if I really thought that pregnancy test could have been wrong. I said that if I took it, it should be positive now, since the ones I have are very sensitive. We though about it. Maybe I should take another one, just in case. So we figured, what the hell? I'll just pee on one more stick.

BFP.

You tell me what is going on.
I guess I'm going in for that HCG test on Tuesday.