Brief Answer:
May be just a boil.

Detailed Answer:
Hi.
Thanks for your query.
Noted your history of being pregnant for 37 weeks, noted a small lump in hair above left ear, just aches with little head cold symptoms but not much. The lump does not move.
From the proper history you have provided this looks to be a boil and needs to be observed. If there is a sign that it is increasing, taking a few days of pregnancy-safe antibiotic is recommended (in view of avoiding any infection). Most of the times such lumps are taken care by the body itself and may not need any treatment other than keen observation and picking up the right time to start treatment.

You may also consult your Doctor to examine the lump and decide either to keep under observation or get treated in anticipation.

I hope this answer helps you.
Please feel free to ask further queries if needed or if you feel that thre is a gap of communication.

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