positive then negative? seriously need some help!

last night I posted a picture of a really faint pink line, the only responses about the picture we're women saying they saw the line. I took one this morning when I first woke up and I can still see the line but it doesn't look that easy to see this time. I'm starting to get a chest cold now which is exactly what happened when I found out I was pregnant with my twins.

so my question is, is it normal to get a positive then a negative? and could i actually be pregnant and should I keep testing. I'll post some pictures so you can get a better look at what I'm talking about. the first picture is from last night. and the second is from this morning.

can anyone give me some insight and some advice/ experience maybe?