BFP (Digital) followed by 3 BFN's. What gives?

[PseudoDiva]

(I posted this in the TTC forum too...not sure which is the right place, but at any rate I am adding some more info.  

I am 15DPO, day 30 of my cycle. Average cycle length is 30 days, we DTD on day 13. I am pretty sure I O'd on day 15, but not positive, because I am only monitoring CM. According to my CM I *might* have been fertile on day 13, but I am not sure. I am breastfeeding my 11-month old and it's been only very recently that he started sleeping through the night. I've had my period back since 3 months PP. 

This morning I took a Clearblue digital test and it was positive. I was in shock. A few hours later I tested again just to be sure, again with Clearblue. This time it was negative. 

I did some Googling, realized that CB has been associated with a lot of false positives, and decided to go buy a couple different brands just to be sure. 

I tested with another generic digital and a standard two-line test. Both were negative. 

So, to recap, I had only one positive. Then I had a negative with the SAME brand. Then I had two more negatives. 

Any ideas? Has this happened to anyone? Am I pregnant or have I spent my whole Saturday worked up for nothing?

PS--Yes, I have seen peeonastick.com and it's very helpful...just wanted to get opinions from other people!  

[RoseRedHoofbeats]

I vote it was a false positive. At CD 30 and 15 DPO you should be able to get a positive on pretty much any test on the planet if you were really pregnant.

~Rose

[PseudoDiva]

This morning I tested again with FMU and got a clear second line.  Sounds like it might be the real deal...

[RaraAvis]

I guess you could have gotten an early BFP with FMU, then had more diluted stuff later in the day -- but I'm surprised you'd get false BFNs 15 DPO -- it seems like FMU wouldn't be necessary at that point.  

I was all set to chime in on the false positive bandwagon until I saw that last post!  Are you going to test again tomorrow morning?