Multiples??? does this sound possible?

Lmp may 4th. Ovulation was 19th. Bd on 11th, 15th, 17th, 19th, 22nd, 23rd, 25th. I had a faint positive a couple days ago. Took another test yesterday with FMU and was negative. AF has not shown. No spotting or cramping. Talked to my dr and scheduled to see her in a few days. Told her about pos then neg but no spotting or cramping. She mentioned that since multiples run on both sides it is possible that I was preggo with multiples which triggered an early pos but had chem preg with one which is why neg now. She's thinking I am still preggo with at least one. Has anyone heard of this before? Don't want to get my hopes up unnecessarily. Any opinions are appreciated.