flutters

I have had 2 mc and have been ttc. I have been tracking but this month took ovulation test and had sex the day I ovulated. My boobs have been tender but are not aching and I feel they should if I'm pregnant. I am only 11 days past my ovulation day when we did the deed. I have been nauseous today but not thrown up but I just had a wierd flutter/vibration in my lower belly. has anyone had this before? by the way I got to anxious and took a test 3 days ago and it was negative which made me sad but when I started thinking I would have only ovulated 8 days before that. it may be too early to show up. any thoughts?