I feel crazy! positive in evening, negative in morning

I have been getting positives and negatives on tests throughout this week. I took a digital test yesterday in the evening and it said pregnant. I took another one this morning and it said not pregnant. My husband and I have been TTC since March. I think my doctor probably thinks I'm nuts with all of the blood tests I have done since then. I went ahead and did a blood test this morning. It's probably going to be negative, but I've already missed my period so I don't know. Ugh! I just don't understand. BTW thanks for letting me vent. I'm trying to surprise my husband when it finally happens so this is a good place to talk to others about it.