Pgs embryos failing and multiple mcs

I posted yesterday. This was my third transfer with pgs embryos. My first two frozen transfers were bfn with one pgs embryo each time. My embryos were thawed tested then Re thawed and my Dr is worried our quality was impacted. For this third fet with pgs embryos we transfered two. I was also on lovenox and prednisolone. My beta at 13dp5dt was 166 and at 15dp5dt dropped to 122 and I've been cramping and spotting brown. I'm staying on meds and will repeat beta at 17dp5dt but my beta is way too low for this to even be a vanishing twin at this point. My question is at this point is it best to try and transfer more embryos from this batch or do another retrieval and this time pgs test right away?