what could this be?

I

had two 5 day early blastocysts transferred on 22nd August. My test day is this Saturday 2nd September. I have no real symptoms as yet. Yesterday I went to the toilet and although there was no discharge when I wiped, there was this small amount in the toilet bowl (photo one - sorry for tmi). No blood in it. In the evening i had a slight brown lump of discharge (second photo) and also had an ache at the bottom of my back on the left sode. Today I've just been to the toilet and had this when i wiped (photo 3) Any ideas what this could be? I am tskonf lubion injections so my mind is thinking it is just a side effect of the progesterone:(