Could touching the clitoris and vagina from outside with precum result in pregnancy?

Hi doctor,

Sorry for my long question but I am so worried, and confused and need your assurance and clearance. I had sex with my girlfriend twice with full protection. I washed in between but I am afraid that the second time we had sex, I did not wash my hands and penis so well though I had used water and soap. I do not remember exactly what I did.

After an hour or more, when I was resting and eating, I felt sexually aroused again and I squeezed my penis and a drop of precum was on my finger. I wiped it fast with my penis to lubricate it and then I touched the clit and vagina of my partner from outside to excite her. I am afraid that my precum drop would have had some sperms from my last ejaculation which happened an hour prior to the incident and cause her to be pregnant.

Can this make her pregnant? I wiped the drop on which I lubricated my penis before touching her. Please note that my girlfriend had Depo-Provera injection only once seven months back and four months back she was supposed to repeat the second shot, but she did not as she had black blood and discharges. Till now, she is having pink discharges and sometimes heavy bleeding and always she wears a tampon. She mentioned during our last protected sex (which was last week) that she had mild bleeding on the same day we had sex.

After four days, she told me that she had massive bleeding for two to three days and the bleeding resembled her period blood, but she does not know anymore since her period is not regular anymore. Since she stopped the Depo-Provera birth control injection, she has had continuous discharge and bleeding.

She does not know if the bleeding could be period blood or not. Also, she does not know anymore about her cycle since she stopped taking the birth control injection four months back and does not know if she is ovulating or not. She is still bleeding even today and experiencing a discharge.

My concerns are as follows:

1. Could the massive bleeding that occurred four days after us having protected sex and touching her clit from outside with a small drop of precum indicate implantation bleeding or could it be a normal period pain? She told me that she had heavy bleeding which leaked through her pad.
2. If she is still bleeding and experiencing continuous discharge, could it mean that her uterus is currently nonfertile and does not produce eggs as she is bleeding?

I made her do a test last week within eight days after protected sex and today is the 10th day. Shall I ask her to take another test? The result of the test taken on the eighth day after the incident was negative. I was said that the result would be more accurate between the 10th to 14th day if she does not know her period cycle. Please help.

Thank you.