last night when i was getting ready for bed i noticed my eye was a little pink/red in the corner. i didnt think anything of it and figured it would be gone in the morning. well its still pink in the corner, not really any better/worse. it doesnt itch or water or anything, its just pinkish/redish in the corner. is this pink eye? or could it be an allergic reaction?

i did use an older mascara i havent used for a while last night...could this be it? should i go to the doctor?

thanks in advance