I am so confused!!!

Okay... So my cycle is always 27 or 28 days like clock work.. This month I started day 24 very light and only for three days. I didn't think much of it until I started feeling a bit dizzy and had increased urnation. I took a test today and had a VERY faint positive....  I just left seeing my midwife she did a hcg and progesterone blood draw so I should know in the morning what my levels are.... until then does anyone have experience of having early bleeding then having a faint line 8 days later??? I feel as though the line should be really dark if I'm still days after when my period would have been due. Please help! In going to be going nuts until the morning!