Visit to the ER and Beta #3

Had to go to the ER for spotting to get a Rhogam shot. My beta was 780. U/s showed no gestational sac...Have to repeat quant beta in 2 days. Praying it's not ectopic. The doctor said the hcg  doesn't indicate ectopic, but it has slowed down to doubling at 70 hours. She said they don't normally see anything on u/s until betas are at least 1000. However my lab paperwork shows they could not rule out ectopic either since this is a PUL. So another beta for me on Friday. They also saw a small fibroid, so I am wondering if that is what is causing the spotting. Strange because on CD 10 my RE said my saline sonogram was flawless. He is the one who caught the first fibroid I had removed in 2010. He has an eagle eye so I know he would have seen it.