Faint lines...

So on Monday 11/27 I got my BFP. I took a regular and digital and both were positive. I did a blood test the following day and on Wednesday the nurse said my count was 59 so I was definitely pregnant. Now back in March same thing. Missed period on Saturday, BFP on Monday, (no blood test), by Friday I had a pink discharge and by Sunday I was bleeding and got a negative hpt. So it's like deja by here. Missed my period on Saturday (Which ironically was my March pregnancy due date), BFP on Monday. I took another test today hoping the line would be darker and it wasn't. Tomorrow is Friday so I am getting nervous as the memory of my last miscarriage is still fresh in my mind. I have another blood test on Monday but the anticipation is killing me. I guess my question is has anyone else had a normal healthy pregnancy where the line never got darker? I have seen some tests ladies have posted where it has. Some articles I read say no. I just want to calm my mind a bit.