Implantation bleeding????

Today I had this weird clearish/brownish discharge. N then alil later it was clearish pink. Really light spotting that I only got when I was wiping. I only had sex twice this month. I had sex on my highest day. The 16th. N I had weird vaginal cramping today also. The spotting has already stopped. Idk what it's from or if it's implantation bleeding. I haven't started yet. My last cycle was 35 days. So my periods r irregular. Can anyone help?! Please