Implantation bleeding?

Hey ladies, so my sister is currently trying to get pregnant. She has tested for ovulation everyday since Saturday and it’s just been “high.” Yesterday morning when she wiped she had some red blood, like spotty but it was the tiniest amount and only on the toilet paper, this morning, same thing but it was brown blood just on the toilet paper. She thinks this may be implantation bleeding and I’m thinking possibly too. Any insight from anyone who may have experienced this before?? We’re you pregnant? Not pregnant?