Implantaion bleeding? And low blood sugars?

Did any of you experience implantation bleeding before finding out you were pregnant?

My husband and I have been TTC for 4-5 months now. My period's not due til tomorrow, but my body's gone wacky already...hoping it's a good thing! Two days ago I started spotting brown (sorry TMI). I've never spotted before my period and brown!?! Yuck. It was just a little bit for two days and now it's stopped. And yesterday all of a sudden my blood sugars plummeted. For about a week before my period I've always set my pump on a 60% increase, right when I start my period my BG drops, and then a day later or so I take the increase off my pump. I haven't started my period yet, but my increase is already off and I'm still experiencing lows. Not like me at all. I've taken a hpt this morning, but it was negative...still a little early yet I reckon.

Anyone else experience this - brown spotting and/or low blood sugars before their missed period? 

Thanks all! 

I had one little spot the day I was supposed to get my period. I had some extremely low blood sugars between then and 2 days later when the pregnancy test was positive (I passed out and had a seizure). It sounds like a possibility you might be pregnant! Good luck! =)