Hi, okay... so my situation i need some advice !

I had my period from the 20th of March, until the 23rd of March

I had unprotected sex on the 30th of March, but he did not ejaculate inside me.

My next period was due around the 21st of April (it did not come this day) i then had unprotected sex on the 22nd of April, sorry for tmi, but he ejaculated (not inside) and then we done it again (no bathroom breaks)

My period still had not come, so i took a pregnancy test on the 4th of May and it was negative.

It is now the 9th of May, still no period and when i wipe i experience this (picture to follow)

Could this be the start of my period? Does this look like implantation bleeding? When could i take another pregnancy test?