Can someone explain to me the difference between a chemical pregnancy and a miscarriage?

In August 2018, I got pregnant with my second baby. In October I ended up having a miscarriage. Thought I was 11 weeks but the baby was measuring 6 weeks. Miscarried naturally a few days after finding out.

Got pregnant again in March 2019. Took a pregnancy test the day before i was expecting my period and got a faint positive. That was on a Thursday. Friday I was having mild cramps on and off and thought it was normal. Had sex that night. Woke up on Saturday to a little blood and knew that pregnancy was ending.

I’m just wondering if the second one was a chemical pregnancy? The lady I talked to at my clinic (not a doctor) said that women who have chemical pregnancies need help getting it started and passing the tissue, but I just feel like that’s not true because from what I’ve read a chemical is when the fertilized egg doesn’t fully implant so then your period begins which is exactly what happened to me this time. The first time I was having full on contractions and there was ALOT off blood and i bled for two weeks. This time there was not pain, not heavy bleeding and just bled for 5 days which is exactly like my regular period. I’m just confused.

Sorry this is so long 😬