Pregnancy after surgery

I just under went a surgery in October to remove a small amount of scar tissue and culterize a small amount of endometriosis to see if this was the cause of the inability to become pregnant.  I took a cheap pregnancy test this morning and it came back positive.  My husband and I picked up a first response test this afternoon and I took that one later in the day and again another positive. The one line on this one was lighter than the first line. After two test should I be assuming that it means we are pregnant?