Are my eyes playing tricks???

Laura
Hello friends
I wonder if anyone can help me. I have been ttc for 15 months with never a sniff of a positive. As this test was developing I definitely saw a second line but now the 3 mins are up I'm not so sure... when I tilt the test at different angles I feel that I see it again but it may be my eyes playing tricks on me as I'm so desperate to be pregnant!!! My period is due today. Can anyone help? Thanks and baby dust to all xxxx