Any thoughts?

Me and my dh have only being ttc for a couple of months, my period was due yesterday but no normal symptoms have appeared but i have had really tender breasts and lower back pain for around 10 days. On Friday night I had sharp pains on my lower right hand side for a couple of hours and then it disappeared. I have had slight spotting this morning but it soon went away. I normally get really bad stomach cramps with af but nothing at all. I am currently 14 dpo and have had 3 bfn’s! Any thoughts would be appreciated.