Threatened Miscarriage/Ectopic. Low HCG

Hey Guys! Looking for someone who has ever experienced something like this. This is my 5th pregnancy, and I have one live birth. All of my miscarriages have been in the first trimester, prior to 9 weeks. This time, I know exactly what my dating is like because my husband was working away from home and we only BD one time. I should be 5 weeks 4 days. My HCG has been low and slow rise. My betas are drawn often because of my high risk of recurrent loss. I got a positive hpt at around 10 DPO and then the following day, Dec 23, I began 3 days of heavy bleeding. I thought it was a chemical pregnancy, so I went in for more bloodwork to verify. I was found to be still pregnant with low HCG, although it was rising quickly with good doubling times. It's been a roller coaster with low HCG and now it's going up and down.