Someone help please

Christa
My period is seven days late. I tested on day four and then yesterday, the morning of day six. Both tests have came back negative. My period is usually never late, and if it is it is by a day or two. My breasts feel a little heavy and I'm eating a little more than usual. I've felt nauseous for about a week now, but it's off and on through out the day. I'm bloated and constipated. About a week ago I had some darker than normal bleeding but it only lasted a little while and was not enough to cover a tampon (very much unlike my normal periods). I also had some bright pink blood after my partner and I had intercourse a few days ago but that just showed up when I went to the bathroom. I haven't bled anymore since then, I've just had a lot of mucus down there. Could I be pregnant even with the two negative tests? My boyfriend and I are TTC so no protection is used.