BFP yesterday and BFN today?

Yesterday afternoon I took an early response test (rite-aid brand) and it was definitely a BFP. I had a tiny bit of spotting yesterday evening. Today I took a First Response Rapid Result and it was a BFN??? My AF comes every 28-35 days... Today is cycle day 32... I'm kinda freaking out. I'm hoping it just has a higher sensitivity? I had MC in February and want nothing more than to conceive and have a healthy baby. Any advice or insight would be greatly appreciated!