10 days left - advice welcomed

[user1492635613]

I am usually like clockwork with my periods and am now 10 days late.

Had unprotected sex just a couple of days after my last period about 2 or 3 times. Have been travelling for 2 weeks to Sri-Lanka and the Maldives and been back for nearly 2 weeks but haven't come on.. I've had cramping sensations and a little brown ish coloured discharge.

My nipples are so sore and painful and boobs feel a bit different, OH says I am very snappy and feel generally tired. I've taken 4 tests and all have come back negative, so really don't know what to think !! I'm 28 have been trying for nearly a year now and nothing has happened

Any experiences or advice is welcomed xx